The Juicy brake turkey warble/vibration MEGA THREAD- Mtbr.com
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  1. #1

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    The Juicy brake turkey warble/vibration MEGA THREAD

    I figured since this problem is so widespread it deserved its own thread. So if anyone has this problem post up here. Hopefully we can find a real cause/solution to this problem.

    So here's the info we have on the problem:

    *Usually only the rear brake makes a loud squealing noise, that may sound like a turkey warbling.

    *The noise is accompanied by a vibration that can be felt throughout the bike, including the saddle and handlebars.

    *The brake works fine despite the terrible noise.

    *Some people have done nothing and the problem eventually cleared itself up. Possibly from breaking in of the pads and rotor. Others have had no luck after the brakes should have broken in.

    *Some people have cleaned, sanded, or replaced their brake pads and the problem cleared up. Others have done all of the above to no avail.

    *Replacing the rotors with the same avid rotor, another brand rotor, or another size rotor has fixed the problem for some, but not all.

    *Anti-squeal brake spray for cars has solved the problem for some, but many do not recommend this treatment because it supposedly contaminates the pads.

    This is all I can think of off the top of my head. Let me know what you guys can come up with and I'll add it to this post. Hopefully we can come up with a solution!

  2. #2
    ride hard take risks
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    Quote Originally Posted by johnniewalker85

    *Anti-squeal brake spray for cars has solved the problem for some, but many do not recommend this treatment because it supposedly contaminates the pads.
    Anti-squeal goes on the back of the pad it does not contaminate the pads braking area.
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  3. #3
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    Anyone shim out the calipers a little????? Looking at my rotors I see an 1/8" or less of space with no pad contact on the outside rotor surface and on the inside I see that the pad contact area is off the disk and on the spokes?arms? of the disk by about the same. Under regular braking no problems but under hard brakes I get the pulse/grab. Maybe the pad angles in on hard brakes and the pulse is when it strikes the spokes holding the disk??
    I don't know? should be this difficult to get some smooth brakes!
    Yes new g2 rotors and new pads are on it. Brake bleed done as well.

  4. #4
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    if your getting this problem, call avid. We have had a couple customers come through our shop with this problem and everytime avid has made it right by either replacing the rotor or in some cases the entire brake system

  5. #5
    dweeby
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    I had probs both front and rear and nothing would stop it untill after a year of messing around with washers, changing the bolts to stainless steel etc I found these pads. The name may be daft but they worked for me. Cheap and silent.
    One other thing, although copper grease dose go on the back of the pads, the original Avid pads have holes in the backing of the pads and it WILL work through to the pad. I found out!
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  6. #6
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    I'm having the turkey trouble with my rear avid juicy 5. So far I've tried sanding the pads, cleaning the rotor, and re-calibrating them (loosen mounting bolts, sqeeze the brake lever and re-tighten), to no avail. Sometimes it goes away but always comes back. I've noticed a very slight warp in the rotor which I suspect is the source of the problem. I'm going to call avid as sugested above and see what happens.

    One other thing I notice which may or may not be related--my casette wobbles quite a bit as the whell turns, which I've read is fairly normal, but I wonder if it contributes to the apparent rotor warp. I wonder this because when I remove the rotor and lay it on a flat surface I see no warp, I can only see it when I peer down the rotor as it's spinning on the wheel, in relation to the pads. Just a thought but I wonder if there is a connection here--I also wonder this because it seems to be more common on the rear wheel.

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    Rex that's a good point. But could it be that everyone who has the warble is having it because of wobble in the rear hub?

  8. #8
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    For what it's worth.

    The Juicy 7's (2007) on both my wife's and my bike developed the hated "turkey gobble" after about 6 months of riding on both the front and back brakes.

    BOTH brakes were fixed after doing the following:
    - bleeding the system.
    - changing the rotors to non-Avid (one has Galfer and the other Hayes)
    - changing the pads (Galfer on the Galfer rotors and Avid organics on the Hayes)

    A year later...
    we both still have no noise issues and great braking.

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  9. #9
    narCOTIC
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    I just got some superstar components pads for my carbons (although i didn't have the turkey thing going on, i did have some noise back there), and they are completely silent after a few rides! They are real cheap too, and have much better modulation than the stock avid pads

  10. #10

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    The turkey comes and goes on my 08 Juicy 7's, all standard aint touched a thing, one day it's there one day it aint.
    Braking is fine so it doesn't bother me, it's a relatively low sounding squeal, if it was real high pitch I would be doing something about it sharpish.

  11. #11
    LCW
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    After about probably 80miles - my Juicy 5's (185/160) are working AMAZING!! Initally they were a little bit noisier, but nothing out of the ordinary. A hint of squeak once in a while on the front if there's a bit of moisture. Otherwise very quiet and amazingly efficient and powerful. I'm very satisfied with my J5's!!

    (check out this vid from the collective on the saint brakes http://www.thecollectivefilm.com/pro...ground_qt.html
    - check out towards the end when Vanderham does his run - that is way noisier than my ever were... just to put in perspective)....

  12. #12

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    Quote Originally Posted by MI_canuck
    After about probably 80miles - my Juicy 5's (185/160) are working AMAZING!! Initally they were a little bit noisier, but nothing out of the ordinary. A hint of squeak once in a while on the front if there's a bit of moisture. Otherwise very quiet and amazingly efficient and powerful. I'm very satisfied with my J5's!!

    (check out this vid from the collective on the saint brakes http://www.thecollectivefilm.com/pro...ground_qt.html
    - check out towards the end when Vanderham does his run - that is way noisier than my ever were... just to put in perspective)....

    My Juicy 3s are about as noisy or maybe more noisy than the ones in the video. Still haven't figured out a fix. I might try to ride them and see if the break in.

  13. #13
    Not dead yet, just playin
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    Make sure one of the pistons isn't sticking in the caliper. I've found that J7s work best when the rotor isn't deflected at all. Over time, a piston will start to get a little sticky in the caliper and not move as much as the opposite piston. This results in the rotor being deflected over to the "sticky" side and after a short time, uneven pad wear. Once the pads start to wear at an angle, it goes bad quickly. New pads fix the problem temporarily, but it doesn't take long for the new pads to wear at an angle if the piston is still sticky.

    So, pull the pads out and squeeze the lever a few times. Look to see if one of the pistons is moving more than the other. If one is sticky, hold the other piston in it's bore with a tire-lever or screwdriver and pump the lever, forcing the sticky piston out. Make sure to not push it completely out of the caliper. I drip a couple drops of DOT fluid where the piston meets the caliper. Push the piston back in and repeat until both pistons are moving equally.

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  14. #14
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    You need a couple of small washers to bring the caliper out/up a bit. The cause is from the brake pads grabbing the rotor arms slightly, you need to get the pads rubbing the disc outer only. Braking on the rotor arms gives u the 'gobble' noise. Check the wear on your rotors, if its going down the arms slightly, get it up using washers

  15. #15
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    I think it's toe-in

    I'm convinced this is a simple pad toe-in problem. In 20 months and 1.5k miles on a pair of J7s with G2 rotors I've had the warble 4 or 5 times, front or rear seemingly equal. For me the problem has occurred 100% of the time immediately or soon after pulling and re-installing the pads or re-centering to correct for a dragging pad.

    The first time it occurred I tried many of the standard fixes people use; cleaning and sanding pads, shimming the caliper out, sanding rotor, specing the installation. All to no avail, still the warble. Then I happened to do a wheel stand on steep step-up and on the next downhill no more Howl ... permanently. What had happened?

    I believe installing pads or spreading them to realign can some times inadvertently cause them to be cocked on the centering pin. This causes incorrect toe-in and incomplete contact with the piston and hence the Howl. If the pad is cocked with the leading edge away from the piston normal braking corrects the issue. if the pad is cocked with the trailing edge away from the piston, normal braking continues to pull it away and the Howl persists.

    The wheel stand on an incline put reverse pressure on the rotors and settled the pads onto the piston. Since that first time I have been able to silence the warble immediately 100% of the time by firmly applying the offending brake and rotating the wheel backward and forward lightly to settle the pad in. These fixes have all been permanent silence for me until I fiddled with the brake set-up for one reason or other.


    This accounts for why all of the fixes people use work or don't in a seemingly random manner. All of them involve operations that can inadvertently cause or correct the pad toe-in issue; sometimes you fix it, some times you cause it.

    Shane

  16. #16
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    Quote Originally Posted by ryan123
    You need a couple of small washers to bring the caliper out/up a bit. The cause is from the brake pads grabbing the rotor arms slightly, you need to get the pads rubbing the disc outer only. Braking on the rotor arms gives u the 'gobble' noise. Check the wear on your rotors, if its going down the arms slightly, get it up using washers
    I don't think this is the cause of the Gobble noise.
    I've checked all the rotors on our two bikes for this and it was NOT an issue as the pads made perfect contact with the rotors.
    Changing the rotors was the only cure that worked for me.

    Further to this, a friend of mine is running Juicys with Shimano rotors (with a much narrower braking surface that Avids) has his pads making contact with the rotor arms...
    no noise.

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  17. #17
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    So to insure that the back of the pads are true with the pistons, lightly apply the brake and push the bike forwards and backwards before you align the caliper to the rotor. What happens when the pad material is uneven-do the pads need to be replaced?

  18. #18
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    HATE THEM. They're on ebay now. I'm getting real brakes like formula
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  19. #19

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    I have Avid Juicy 5's and I have the honking noise intermittently. It used to happen on every ride, usually about a mile or so in. But I only get the noise when I'm NOT braking. If I lightly pull on the rear brake lever it stops but as soon as I release it the noise comes back. So I started cleaning my rotors with MEK after every ride and now I only get the noise occasionally and not even for the whole ride. I read in Mountain Bike Action magazine that Kool Stop pads will help eliminate the noise. So I priced Kool Stop pads and they are around $15 or so, if I remember right. Compare that to replacement Avid pads at around $3 and for 5 times as much it should cure the problem. I haven't gotten them yet because, as I said, the problem has gotten much better. I'm probably going to just keep riding with things as they are as long as the problem doesn't get any worse.

  20. #20
    MNTNBKR
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    Just installed Juicy Three's and my rear brake is making the "gobble" noise as well as vibrating my entire bike when I apply a lot of pressure to it. I've done what everyone else has done including; clean the rotors and pads, reposition the caliper, and make sure the rotor is straight and tightly secured to the hub. Each of these solutions worked for about 1 mile of riding then the annoyance came back.

    Has anyone found a 100% effective solution to this problem, ASIDE from buying entirely new brakes? I like the way the Juicys feel and look and I got a good price on them.
    Durango, CO

  21. #21
    Ridin' dirty!
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    My first AVID Juicy brakes were the 5's and they were constantly suffering from sticky pistons.
    replaced them with JUICY 7 and NEVER had any issues. The only time I had a squeal was in very humid conditions and during maybe a week of brake in time.
    Got Juicy LE carbon now and still no issues...What kind of bikes 'yall have?
    Maybe if the rear end is not stiff enough you can't get them adjusted properly.
    Just my 2 cents anyways.
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  22. #22
    MNTNBKR
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    I have brand new (maybe the problem is the break-in period) Juicy Three's on a hardtail ironhorse frame. Talked to the local bike shop and they said to give them a few more good rides and see if they break-in and the noise goes away.
    Durango, CO

  23. #23
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    Why buy juicies when they all seem to have this problem? My mono mini pros have been perfect from day one. I'm sure formulas would be the same.

  24. #24
    MNTNBKR
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    Because for the front and rear handle, caliper and rotor it cost me 120$. That was less than the mechanical discs had on before. Like I said before, I like the look and feel of the Juicys. I'm also a pretty big SRAM fan. Anyhow, I've got a few friends with Juicys and the guys at the bike shop who ride them who all have said they never experienced this. Odd...
    Durango, CO

  25. #25
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    Magura says that noise and vibration may be attributed to trapped air in the caliper and Hayes states that noise/vibration may be caused by a dirty or non-uniform (fork or frame) surface that the caliper or its adapter mounts to. So first try bleeding the brake. And if that does not work, next have your LBS face your IS brake mounting tabs on your frame. Forks do not seem to suffer from the vibration because their lowers are casted with much tighter and more consistent tolerances.
    Last edited by bwalton; 07-11-2008 at 05:15 PM.

  26. #26
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    I have a set of Juicy's on my 08 stumpjumper... they tend to gobble after a long descent then have a chance to cool.

    I'm assuming its due to build up on the rotor after heating to sizzling temperatures then cooling. the heat between the pads and rotors can sometimes cause a glaze effect that tends to cause fade. when the rotors cool is when you start to get the sequel. I've also noticed that i can usually get it to stop after a few hard brakes when the rotors are squealing,

  27. #27
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    I wonder

    I wonder if anyone with BB7s has this problem? BB7s and Juicy 7s use the same pads. But not the same rotors. The rotors for the BB7s are quite a bit thicker.

    I have been running the J7s for about 3 years now on 2 bikes. On my Giant NRS, no noise, running the 6" rotors. On my Ventana X-5 running the 7" rotors, I never had bad noise until I moved back to the west coast. I would occasionally get the turkey warble. But, not big deal, they still seemed to stop me effectively.

    But, moving out to Monterey....the rear brake on my X-5 has been all kinds of trouble. While in Downieville, it sounded like a cross between an angry moose and an angry goose. Braking was absolutely not effective and I could feel it resonate through the entire frame of the bike. On the front, at times it feels as if the pads are popping over each of the slots in the rotors...alternately grabbing and not when it hits a slot, but no real decrement to braking performance.

    As the back brake on the X-5 was worse, I have tried all kinds of things. Emery cloth to the pads and rotors. Shimming. Torquing to the torque specs. Plastic washers. The only thing that seems to help thus far has been organic pads. Still noisy when it gets dusty, but not as bad and it retains most of the braking performance.

    For my problems, my theory is this: Vibration. If you treat the caliper, rotor, hub, and rear swingarm/triangle as a spring/mass system...it will have certain natural frequencies in which resonance occurs. Throw in some contaminants on the pads, and you just may happen to hit that natural frequency easier. The same pads and rotor design on both of my bikes, but one makes the noise and one doesn't. The only difference are the spring/mass characteristics of the system as a whole because one has the 6" rotor, the other a 7" rotor, they both have the same rear hub, but the swingarms are vastly different.

    I have plenty of friends running the BB7s. None seem to share my problems. And, if you look at the rotors that come with the BB7s as opposed to the J7s, the BB7s look much more robust. And heavier...giving it a different frequency at which resonance occurs, partly due to the mass alone.

    I am going to try a 6" rotor on the back of my X-5 this weekend. After that, maybe a BB7 rotor...then maybe I'll try some Galfer pads and/or thier rotor.

  28. #28
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    I've about had it

    After 2 yrs of constantly re-sanding the pads/changing pads, re- setting the alignment, tightening everything, my rear brake squeals like a stuck pig after 80-100 miles. Every time I think I've cured it, it comes back, in a couple of rides.

    I've never had a problem in the front, only the rear.

    2006 J-7's with the Polygon rotor.

  29. #29
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    Okay, inspired by the tread, I threw some washers on tonight.

    Quote Originally Posted by onbelaydave
    After 2 yrs of constantly re-sanding the pads/changing pads, re- setting the alignment, tightening everything, my rear brake squeals like a stuck pig after 80-100 miles. Every time I think I've cured it, it comes back, in a couple of rides.

    I've never had a problem in the front, only the rear.

    2006 J-7's with the Polygon rotor.
    I noticed just a "very" slightly different wear pattern front to back and stuck ~ 3/32" worth of washers under the rear CPS mount and re-aligned as usual.

    The rear is now the quietest, smoothest it has ever felt; better than the front for now. One finger/ 4 oz pressure to lockup/skid the rear tire. I took it out for a short test ride, re-bedding the pads with about 50- 60 stops. Only time will tell.

  30. #30
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    I believe the nasty vibe comes from the pad engaging the rotor out of alignment. The manual for J7's says to align by clamping the brakes then tightening the CPS bolts. I've noticed that this does not guaranty the caliper is aligned.

    I believe it's important to visually align by looking at through the top opening of the caliper first, then clamp down on the brakes and tighten the bolts.
    Question to a custom frame builder..."So what makes your bikes climb better?"....his answer, "Uh, your legs?"

  31. #31

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    Quote Originally Posted by HTail
    I believe the nasty vibe comes from the pad engaging the rotor out of alignment. The manual for J7's says to align by clamping the brakes then tightening the CPS bolts. I've noticed that this does not guaranty the caliper is aligned.

    I believe it's important to visually align by looking at through the top opening of the caliper first, then clamp down on the brakes and tighten the bolts.

    I've tried basically every adjustment I could. still the same problem. I even took off the caliper and sanded the frame where the caliper mounts to the bike. still the same problem. I went to a LBS and they said the pads must be contaminated, even thought I've never touched them and I cleaned the rotors and pads with alcohol. They looked at me like I was crazy and they'd never heard of the problem. They basically just told me to bring the bike in and offered to sell me pads for $22 a set.

    If I bring the bike in they'll probably tell me to replace the pads and/or rotor so I'll probably be like $70-$80 in by then. I might as well just get BB7s or something for that money.

  32. #32
    LCW
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    had a slight gobble develop on the last ride on my J5's... so before today's ride loosened the caliper bolts, had a buddy apply the brake lever and hold it, while I retightened the caliper bolts... went on a good ride today... quiet as can be... I guess I'm in the minority but I'm loving my Avids... one figure braking, good modulation, technical descents in full control. This method to align the caliper (shown in the Avid user manual - which you can download the pdf from their site) seemed to work great for me and I haven't even changed pads (I do like the braking power the stock sintered pads provide, although might try some EBC green or red in the future). Overall quite satisfied w/ my J5's

    peace
    Last edited by LCW; 07-14-2008 at 06:14 AM.

  33. #33
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    I've been chasing the same brake ghost as many of you. I've changed pads, realigned, sanded, beveled etc w/o any success. It is driving me crazy, and puts a damper on my rides. I'm ready to try the BB's--are there any real drawbacks to the BB's?

  34. #34
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    In my experience, proper alignment (make sure you can see light pass through both sides of the rotor) along with replacing the pads and rotors should usually solve most issues.
    Simple | Proven | Reliable

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  35. #35
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    Same turkey warble coming form my '08 575 w/J5s. First bike with discs so I am a bit clueless.
    Probably about 8 rides on it so far and while it is getting a little better it is still annoying. I have tried realigning the caliper, cleaning the rotor w/alcohol and squeezing the brakes while rolling the bike backwards. No luck. I am ready to try sanding the pads. What grit paper are folks using?
    Also, Is it a problem to have the bike upside-down to remove the rear tire? I have read that this isn't great for disc brakes.

  36. #36
    ride hard take risks
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    Quote Originally Posted by SAR13
    Same turkey warble coming form my '08 575 w/J5s. First bike with discs so I am a bit clueless.
    Probably about 8 rides on it so far and while it is getting a little better it is still annoying. I have tried realigning the caliper, cleaning the rotor w/alcohol and squeezing the brakes while rolling the bike backwards. No luck. I am ready to try sanding the pads. What grit paper are folks using?
    Also, Is it a problem to have the bike upside-down to remove the rear tire? I have read that this isn't great for disc brakes.
    Slap the pad on the cement and sand in a figure eight till deglazed.

    Yes you can turn your bike up side nwod.

    Galfer red pads are awesome.

    http://www.pricepoint.com/detail/149...e-Pads-Red.htm

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  37. #37
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    I had the same issue with my J5's. I didn't even mind the turkey warble, it was the violent vibration that worried me. I switched to some Shimano rotors, and all problems immediately went away. I've since switched to the newer Avid rotors and all is still well.

    I'd try swapping rotors or wheels with another bike and see how that works. It's an easy thing to check.
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  38. #38
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    Quote Originally Posted by dogonfr
    Just looked at the Galfer pads from your link they don't come with springs so my guess the stock Avid springs are ok to use with the Galfer pads?

  39. #39
    ride hard take risks
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    Quote Originally Posted by XC Mike
    Just looked at the Galfer pads from your link they don't come with springs so my guess the stock Avid springs are ok to use with the Galfer pads?
    That is correct.
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  40. #40
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    I have '07 Juicy 7's on my GF HiFi.

    At about 200 miles the rear brake started howling. Cleaning/sanding only helped for a few miles. I changed the pads to Kool Stop's and all was well for the next 500 miles.

    Avid organic, Kool Stop, Galfer red and green pads, sanding/cleaning pads/rotor did not help this time. I switched the rear rotor to a Galfer wave rotor and I am using Galfer red pads (the green were too grabby for my taste). Quiet as can be for now after about 30 miles. Time will tell.

    FWIW, the caliper and rotor have always been properly aligned and torqued. Suspension pivots are not worn and are properly torqued.

  41. #41
    drbarky
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    I just spoke Tech Support at SRAM and they were very willing to try and help. They said that they will send out a new rotor and pad(no charge). They wouldn't send them directly to me, but to any SRAM dealer, whether you bought it there or not. So, I called the shop I bought it at, and they will call Tech Support and request the rotor/pads. The gal I spoke w/ said that if the rotor is "out of spec" at all, it can set up this problem. They have a new rotor she said. . The tech number I used is 312-664-8800. I hope this switch in rotor and pads helps, me and everyone else. I have a 185mm Avid CSG2 rotor currently.

  42. #42
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    I have Juicy 5's and they've always been noisy. I've had every issue stated in this thread, until last week when I changed my rotors to Alligator Serration's and got some Kool Stop pads. Now they're quiet as can be and they feel like they stop better. Before, if I had to use the brakes a lot on the trail I could notice them losing stopping power. Now that isn't a problem either.

  43. #43
    LCW
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    Quote Originally Posted by sixate
    I have Juicy 5's and they've always been noisy. I've had every issue stated in this thread, until last week when I changed my rotors to Alligator Serration's and got some Kool Stop pads. Now they're quiet as can be and they feel like they stop better. Before, if I had to use the brakes a lot on the trail I could notice them losing stopping power. Now that isn't a problem either.
    which Kool Stops did you get? The D270 (red backing plate), D270A (aluminum backing plate) or D270S (copper backing plate) ?


    cheers

  44. #44
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    Quote Originally Posted by MI_canuck
    which Kool Stops did you get? The D270 (red backing plate), D270A (aluminum backing plate) or D270S (copper backing plate) ?


    cheers

    D270's

  45. #45

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    I'm going to call Avid tomorrow and see if I can get them to send me a new rotor. It's been less than a year since I bought the bike. It probably has about 100 miles on it. Most of them are me trying to break in the brakes.

  46. #46
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    Quote Originally Posted by johnniewalker85
    I'm going to call Avid tomorrow and see if I can get them to send me a new rotor. It's been less than a year since I bought the bike. It probably has about 100 miles on it. Most of them are me trying to break in the brakes.
    My experience has been thus :
    I won a set of 2008 juicy carbons. I mounted them, but the rear hose was short. LBS redid the line and the brakes have totally rocked in all ways. So much so I bought a "new" set on ebay for my hardtail. Turns out they were New closeout 07 stock. I mounted these also, and I have the turkey warble in the rear sometimes also. I think it may be a rotor issue?
    Hasnt bothered me alot really. Maybe there is some change to the new stuff?
    Anyone know For Sure the year of the brakes they have, not when they got them?
    CDT

  47. #47
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    Well, after stumping most guys wrenching, and while waiting for SRAM to send me a new rotor/pads as noted earlier--out of sheer frustration I bought a new pair of Avid Organic pad and the shutter/squeal disappeared. I rode about 15miles last night and have not had any issues--so I'll shelve the new parts when they arrive and use them if needed. I'm thinking that the pads are a little softer so they don't set up the same vibrations. Just for others knowledge--the other pads I tried were Avid regulars, Aztec organic, Galfer Red as well and the whole realigning of the brake, sanding, cleaning etc of the rotor. The bike I'm on in is a Santa Cruz Blur LT(07/08 model) Good luck.

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    well I swapped my front rotor for the back and put the back rotor in the front. The front is still quiet while the back one still howls. I'm going to try swapping the pads front to back now and take it for a spin around the neighborhood. I'll post my findings when I get back.

  49. #49
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    Man I've tried everything that is posted here about the juicy's. I switched rotors just like johnniewalker85 did and same thing, warble is still in the back. I think it's time to just try formula's or hope's.

  50. #50
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    Quote Originally Posted by miketech1
    Man I've tried everything that is posted here about the juicy's. I switched rotors just like johnniewalker85 did and same thing, warble is still in the back. I think it's time to just try formula's or hope's.
    Hayes Sstrokers are awesom brakes worth considering.

    http://www.spadout.com/p/hayes-stroker-trail-brake/
    Formotion Products
    http://www.formot

  51. #51
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    Quote Originally Posted by miketech1
    Man I've tried everything that is posted here about the juicy's. I switched rotors just like johnniewalker85 did and same thing, warble is still in the back. I think it's time to just try formula's or hope's.
    Hayes Strokers are awesom brakes worth considering.

    http://www.spadout.com/p/hayes-stroker-trail-brake/
    Formotion Products
    http://www.formot

  52. #52

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    ok guys here's an update. Hopefully good news for everyone. I swapped my rotors front to back and vise versa last night. Rode all day today and the front was still perfect while the back still howled. So I concluded the rotors were not the problem. Tonight I swapped the pads front to back and vise versa...

    The front brake immediately had the same symptoms the rear previously had, while the rear was now quiet as can be. The front brake had the strange notchy-ness as if the rotor spokes were hitting the brake pad. This had previously happened on the rear when moving slowly and braking hard to stop the bike. Now fork vibrated a ton when this happened. The shreaking noise wasn't present but there were some squeaks from the brake. I assume the squealing that I had experienced in the rear was from the frame vibrating. The fork couldn't reproduce the noise because it was vibrating at a different frequency.

    In short the problem seems to have been traced to the brake pads. I'll try to head to the shop tomorrow and pick up some replacement pads. I'll post an update as the whether or not new pads fix the problem.

  53. #53

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    Quote Originally Posted by miketech1
    Man I've tried everything that is posted here about the juicy's. I switched rotors just like johnniewalker85 did and same thing, warble is still in the back. I think it's time to just try formula's or hope's.
    Try switching the pads front to back too. I found that the problem moved from the back to the front when I moved the pads back to front. I'm going to pick up some new pads and see if that solves it.

    With the back pads now in the front the howling changes to a violent vibration/squeaking. A much different sound probably having to do with the different materials of the fork compared to the frame.

  54. #54
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    Fixed it with fresh Organic Pads and new Disks

    I had the same problems on both brakes, front and rear.
    Setup: Juicy 5 with 160mm G2/CS disks front and rear

    I tried without success...
    - changed to a new disk in the front (actually downsized from the larger disk)
    - changed brake pads (to the same standard AVID pads)
    - sanded brake pads
    - cleaned brake pads and disks with alcohol

    Whenever I tried one of the above remedies it worked in the beginning but then after a decent ride (basically a short break in period) the turkeys were back.

    The setup was ok, pads were sitting correctly and calipers moved fine.

    I called AVID support and was pleasantly surprised:
    Brook, the support rep was very friendly and he actually listened to what I had to say. I explained what I tried so far and he told me to try their Organic Compound Brake Pads instead of the regular pads.
    He suggested starting with new pads AND new disks AND they were going to send these at no cost to my bike shop if I have them call in regarding the problem. I did not need any purchasing receipt or confirmation, they just wanted to make sure it is taken care of by one of their resellers.

    So I had Jason from SUN bike shop in Milpitas call in and take care of it (these guys are great btw.) and I had everything within a few days.

    After mounting everything, I did a couple good break ins down our slope and there was the gobble again. I was disappointed first but decided to give it a little longer to see what was going to happen. This was a good decision because the problems completely disappeared after the first ride. Just did like 30 miles with a couple long, steep downhills with the new setup and everything seems fine. If anything should change, I will post here and let you know.

    I considered changing to a different brake manufacturer but my VERY POSITIVE experience with AVID support will keep me a loyal customer unless the problem resurfaces.

    Hope this helps
    Uli

  55. #55
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    I got the same problem here.

    I just installed a few days ago the BB7 185mm front and 160mm rear on my bike. The rear took about 20 miles or so to get to a point where my V-brakes were but the front just doesn't seem to cooperate. It starts to vibrate my whole bike once I start to apply a little more pressure. The Breaking power is finally there after 20 miles on the trail + another 10+ miles on the treadmill with the front brake dragging.

    I readjusted this a dozen times, I don't know what to do with it anymore. Even the bikeshop looked at it and said that I installed everything just fine. I'm about the rip that darn thing of and go back to my old reliable (V-brake)...

  56. #56

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    So I bought new pads. I was sure that pads were the culprit. The noise and vibration stopped until the pads got broken in slightly and then started right back up again. I guess I'm going to call Avid today.

  57. #57
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    I thought I had mine problem all figured out, but after a short ride yesterday it came back, this time 10 fold, now the bike vibrates so violently that I don't feel comfortable riding it. I am going to take it to the shop and see if they can get replacement parts from avid.
    Durango, CO

  58. #58
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    After contacting SRAM and every bike shop in Durango, Colorado it looks like I'm on the same page as everyone else. None of the shops have heard of this issue before and SRAM says to try organic pads. There is obviously an issue between the pads and rotors here and I don't want to keep wasting money on crap just to see if it works. The support rep from SRAM had heard of this before and said that organic pads fix the issue, which doesn't seem to be the solution according to posts on this thread, maybe they should send out free pads/rotors to those who have this problem.
    Durango, CO

  59. #59
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    Going for record consecutive posts in one thread!

    So I called SRAM back again after ever shop in town told me "tough luck, buy new parts", and they are sending new organic pads and rotors to my LBS for free under warranty.

    Kind of weird because I didn't tell anyone how long ago I bought the brakes, even though it was only a few weeks ago.

    Anyway, if anyone else is interested you should call up SRAM customer support. Maybe all the calls about the same issue would catch their attention and they will do something about it.

    312-664-8800
    Durango, CO

  60. #60

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    As I read the first 1st post in this thread, one thought came to mind. As I read further, poster #27 made the same statement. Resonance frequency. If the entire bike vibrates, Res Freq is the problem. Mis alignment of brake parts will not cause the total bike vibe. Change parts and problem should sort itself out. If not, the mounting bracket locations for the brakes are the problem and the frame design is basically flawed. You might also want to look into some sort of rubber bushings for the brake mounts. I have V-brakes and I have never looked at disc mounts very closely so.... it may or may not solve your problem.

  61. #61

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    Quote Originally Posted by Notorious-J
    As I read the first 1st post in this thread, one thought came to mind. As I read further, poster #27 made the same statement. Resonance frequency. If the entire bike vibrates, Res Freq is the problem. Mis alignment of brake parts will not cause the total bike vibe. Change parts and problem should sort itself out. If not, the mounting bracket locations for the brakes are the problem and the frame design is basically flawed. You might also want to look into some sort of rubber bushings for the brake mounts. I have V-brakes and I have never looked at disc mounts very closely so.... it may or may not solve your problem.
    Except the problem is so wide spread across various frame types and brands. Something in the brake is vibrating to cause the frame to vibrate. The bottom line is the brake should not be vibrating.

  62. #62
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    I have found out that if you turn OUT the Inboard knob as far as you can and leave just enough on the outboard so that there is no rub on the caliper (rather than the 1/3 2/3 rule), it seemed to have solved my problem. Mine has just enough space on the outboard side that you can see maybe a crack of light.

    Just to make sure I'm clear..... Turn the Inboard pad (big knob) all the way out so you can see a lot of the pad.... Turn the Outboard pad (small quick adjust knob) all the way IN so that it practically disappears in the caliper, but make sure there is enough MEAT there so there is no caliper/disk rub.

    The violent vibration is finally gone, and I hope its gone for good; well see the next few rides. The front has now enough braking power to lift me of my rear wheel.

  63. #63

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    Quote Originally Posted by johnniewalker85
    Except the problem is so wide spread across various frame types and brands. Something in the brake is vibrating to cause the frame to vibrate. The bottom line is the brake should not be vibrating.
    Yes, I see what you are getting at which why I believe it's the actual rotor material.
    Maybe to eliminate/validate my theory, everyone with the problem of extreme vibration post what metal your discs AND pads are made of along with the frame. I will try to find the resonance freq's of all metals in question and come up with a solution.

  64. #64

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    Quote Originally Posted by Notorious-J
    Yes, I see what you are getting at which why I believe it's the actual rotor material.
    Maybe to eliminate/validate my theory, everyone with the problem of extreme vibration post what metal your discs AND pads are made of along with the frame. I will try to find the resonance freq's of all metals in question and come up with a solution.
    My bike is 6160 aluminum hard tail frame. Rotors are the Avid clean sweep rotors and my pads are the Avid sintered metal pads.

  65. #65
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    I tried switching the Avid G2 Clean Sweep rotors for Hayes round rotors. This seemed to solve the problem for about 1 hour, then the noise and vibration came back.

    So far here is the list of unsuccessful attempts to fix this issue:
    -Re-aligning calipers: FAIL
    - Adding washer to set caliper further from mount: FAIL
    - Sanding Brake Pads: FAIL
    - Cleaning Rotors: FAIL
    - Swapping Rotors: FAIL

    I will leave an update when i install the new organic pads and rotors from Avid.

    From all of my 'tests' I have come to conclude that the pads are most likely causing the issue, hopefully new pads of a different material will work.
    Durango, CO

  66. #66
    LCW
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    have you tried the Kool Stops (D270 - they are an organic semi-metallic I believe), or EBC green stuff (also organic I believe) ?

    also wondering if the G3 rotor (from the upcoming Elixir) are available yet... might be an alternate rotor option since they should bolt right up, assuming the correct dia...

    i've actually had some pretty good luck with mine ('08 J5's), doing the odd realigning of the rear caliper per Avid's procedure every 3-4 rides... i've noticed the harder i use my J5's, the quieter they become - i've got the stock sintered pads in there - major stopping power... also noticed if any bit of moisture, they'll squeal a bit - nothing too major or annoying... perhaps for some people, if they have the sintered pads and don't use much brake pressure or use the brakes hard enough (maybe because they ride mostly flat ground, or not many hills/descents) the sintereds are overkill and the organics come in handy being softer and less prone to noise (while still giving ample braking force for all but the most steep and long descents)...

    Ultimates come with organic as standard... wonder if anyone with Juicy Ultimates has noise issues?


    cheers

  67. #67

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    Quote Originally Posted by johnniewalker85
    My bike is 6160 aluminum hard tail frame. Rotors are the Avid clean sweep rotors and my pads are the Avid sintered metal pads.
    What about the rotors? Are they light-weight steel, aluminum, or other metal? I googled that question for an hour but can't find the material the rotors are cut from...

  68. #68
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    My J5 in the rear has been having this problem since I put it on. I'm running the stock sintered pads. Sanding both rotor and pads works only for very short times, did many caliper realignments, etc... I also noticed that it gets much quieter when I hit them hard.

    I just got organic pads last night (Aztec) and a new rotor (also Aztec). I've gotten everything aligned, and will try it out tonight. I'll post the results tomorrow. My experience has been that by the end of a reasonably long ride, it will be squealing again. So, if it stays quiet, that may mean new rotor and new (organic) pads did the trick.

    If not, I guess I'll have to think about replacing them with different brakes. It is really, really annoying.

  69. #69
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    After one ride with the new rotor and organic pads, my rear brake is silent. There is just a slight crunchy sound, like there is a little bit of sand or something on the pads. I noticed that the organic pads have less stopping power, though. SInce they are new, I figure another ride before they are completely broken in, at which time I hope they stop a little bit better.

    So, do the organics + new rotor help? I'd say yes. Another ride tonight, and I'll be sure. I'm curious if others have had luck with organic pads?

  70. #70
    Ride Everything
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    Avid organic pads and Hayes V6 rotors work really well, IME. Nice and quiet.
    GRAVELBIKE.COM - ride everything

  71. #71
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    Good to know -- thanks MileHighMark.

    My ride today was nice and quiet. There is just a bit of crunchy sound during hard, slow speed braking (tight downhill switchbacks). I still feel a bit less power than with the stock metallic pads, though. I may just get bigger rotors -- currently running a front 180, rear 160. But, I've not tried the organic pads in the front.

    My conclusion, FWIW: Organic pads on new rotors, and careful alignment of the caliper, seem to make the horrible sounds go away. And, the braking is nice, in terms of modulation. Seems less powerful with the organic pads. All of this is in very dry conditions.

    All things considered, I like my hydro xtr brakes on my other bike much better. But, I don't want to spend $500 or more on putting xtr brakes on this bike (SS 29er). Seems like I may stick with organic pads, and just go to 180/180.

  72. #72

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    Quote Originally Posted by fatdave
    Good to know -- thanks MileHighMark.

    My ride today was nice and quiet. There is just a bit of crunchy sound during hard, slow speed braking (tight downhill switchbacks). I still feel a bit less power than with the stock metallic pads, though. I may just get bigger rotors -- currently running a front 180, rear 160. But, I've not tried the organic pads in the front.

    My conclusion, FWIW: Organic pads on new rotors, and careful alignment of the caliper, seem to make the horrible sounds go away. And, the braking is nice, in terms of modulation. Seems less powerful with the organic pads. All of this is in very dry conditions.

    All things considered, I like my hydro xtr brakes on my other bike much better. But, I don't want to spend $500 or more on putting xtr brakes on this bike (SS 29er). Seems like I may stick with organic pads, and just go to 180/180.
    The fact that you're having the noise on an SS takes the frame material out of the equation. The problem is definitely the brakes.

    Thanks for the info. I'm going to call Avid on monday and hopefully get the new rotors and pads sent to me in time for my vacation.

  73. #73
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    Well my rear 07 J5 with Avid organic pads is starting to turn into a mating turkey again. I bled the brake and realigned the caliper around the rotor in hopes that a trapped air bubble in the caliper was causing the piston to vibrate. Unfortunately my theory was wrong. Next I will try a 04 Avid round-a-gone rotor. Then after that I will install a quiet 04 J5 brake. I will post my results tomorrow.

  74. #74
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    beveling the brake pad edges

    Not sure if this would work or not but try beveling the edges of the brake pads with a dremel and sanding tool. Beveling the edges of the pad will eliminate the binding of the pads because there is not a sharp edge to grab first before the whole pad grabs. This might help with the noise. This is something new they are trying in the automotive field to elimate noisy brakes and it works. (Carquest automotive brake pads are starting to come pre-beveled) I know the pads are way thinner then cars but if you are going out to buy new pads anyways then why not give it a try on the old ones first.

  75. #75
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    Beveling the pads has done nothing for me.

    In an earlier post (#40), I stated that switching to a Galfer rotor and red Galfer pads had ended the noise. I now have about 60 miles on this setup and no noise yet.

    I agree with the "resonance frequency" idea that the noise is a function of the entire bike setup and not just the brake system itself.

    The cure will be different for each bicycle. A change of pads fixed it for me for 500 miles. When the noise started again, nothing worked until I changed pads and the rotor.

  76. #76
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    Wink Just another Turkey Story

    I am just adding another chapter to the story- Try to endure this it does actually go somewhere.

    First of all anyone that says they have heard "noise" or squeaks.... from their brakes have NEVER had the wonderful experience of the true turkey wobble or in some cases the mating sound of orca the killer whale. I have read some responses in this thread that obviously have never encountered anything more than a mere glazed rotor or maybe the singing of a damp morning dew on the rotors…. Oh no only those who have actually heard (and felt) the death cry and shudder of the moose know what I mean.

    Anyway here is my experience. I was lucky enough to purchase a Trek 8900 in 98’ and went right from canti’s to hydraulic disc Hays with 160mm rotors, since then I have never looked back- nor ever had an issue (ok 1 warranty item in 98’) with the old school 1rst generation Hays. I have learned a lot since then on how to keep them quiet- like never use brake clean spray or they will squeal like crazy – rubbing alcohol is the way to go, emery cloth to remove glaze, no oil on the pads… most of us have learned this by now but the wild turkey pays no heed- it defies all logic!

    My experience is with Juicy 7’s, 07’s I think. I have two sets of them one set that has been on a 05 Superlight, an 07 Blur XC, and an 07 Blur LT currently and am running them 160mm in the rear and a 185mm to the front on post mounts ( was running 160mm up front on tabs before). Never even one issue- work great no squeaks good modulation and of course no horrendous death cries or shudders.

    The other set was installed first on a 29er Hardtail and they worked fine (IT WAS A CHEAP ON LINE PURCHASE TOO) and again no issues…. I then decided to build up a 26” Hardtail with the parts I removed from the 29er…this is where it all began and why I am even on this thread.

    To the point the frame is a Yeti ARC and I built it up with the Juicy 7’s and to my horror this shudder and noise…this death cry began. I first thought it might be the frame as it is an older model and has the trademark looped chain stays, I did all the old tricks new pads… scuffed the rotors, etc, etc… still the vibration an noise. I found that if I moved (made sure it was not pressed against the frame) the hydraulic line it seemed to have an affect on the noise/vibration. But like so many other “solutions” it was inconsistent.

    I planned on trying 140mm rotors but remembered I had a vintage 160mm Hays rotor and I decided to try it- it worked! But there are a few variables

    1. I noticed that both the outer edge of the rotor (the Avid 160mm G2) and the respective area of the caliper appeared to have made contact. It seemed like just the front portion of the caliper came in contact with the rotor ( like the centrifugal force of the wheel/rotor flexed the bracket/frame enough to pull the caliper into the rotor, which explains the extra washers fixing some issues). Take a look at your rotor an see if it has marks or grooves on the outer edge- This would explain the performance staying the same but also the vibration.

    2. The rear stays seem to line up the wheel off center and I had to “eye” it up to line up so that the tire was centered in the seat/stays. I realize not everyone will have this issue but it could have played a factor.


    I am sorry this is so long but I went about mad trying to figure this out and hope this helps those of you who have had the same issue, Let me know if this makes sense or if it holds no water-

  77. #77
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    I have Juicy 3s and not a problem. If I hit some mud Ill get a gring, usually in the front. I just apply the brakes lightly to wipe the rotor and it goes away.

    One time I did get a funky wobbly but I discovered my front wheel was loose

  78. #78
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    I have just bought some Hope floating saw rotors, 203 front and 183 rear (both with the hope brackets for the correct size). I also have some kool stop pads that i will fit when i swap over the rotors. I will let you all know if the horrendous vibrating i get with my current G2's stops with the new rotors.

  79. #79
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    I've had Juicy 7's on my bike since December of last year without any problems until about 2 months ago when I developed the dreaded noise and horrendous vibration throughout the frame of my bike when applying the rear brake. Like most of us out there, I've tried just about every fix that's been posted on here. Tried different pads, different rotors, multiple combinations of pads and rotors. I've sanded my pads and rotors more times than I care to count. I was completely stumped. Then I got to thinking about it, and the noise started after I changed wheelsets. Then reading the posts about resonance frequencies, I figured that must be what's happening with my bike since I changed wheelsets from cheap OEM with loose ball bearings in the hubs to a set of Mavic wheels. We all know how Mavics sound. My solution was to install small rubber o-rings between my frame and caliper adapter. I can't say that this has completely solved my problem, since I've only had one ride on my "fix". But, it seems to have worked for the time being since my brakes were quiet.

  80. #80

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    Quote Originally Posted by dnoyeb
    I have Juicy 3s and not a problem. If I hit some mud Ill get a gring, usually in the front. I just apply the brakes lightly to wipe the rotor and it goes away.

    One time I did get a funky wobbly but I discovered my front wheel was loose
    It seems like you're in the minority as far as this site goes. Maybe only those with problems post?

    Anyways enjoy your trouble free, noise free brakes! How do the threes work when they work right?

  81. #81

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    Quote Originally Posted by übermensch
    .....My solution was to install small rubber o-rings between my frame and caliper adapter. I can't say that this has completely solved my problem, since I've only had one ride on my "fix". But, it seems to have worked for the time being since my brakes were quiet.
    I mentioned this above in one of my posts as a possible solution! I am glad to hear it may have solved your particular issue. Please, let us know after further rides in various weather conditions how your situation is evlolving. As somewhat of an amatuer scientist/physicist, I am curious. Logic dictates that if applying your brakes make the frame shudder, the mounting point between the two is the culprit. Afixing some sort of rubber or polyurethane bushing to the mounting point should solve the problem.

  82. #82
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    Still not quite right

    I posted earlier that I was having a horrible vibration, not the turkey noise, coming from the rear brake on my Ventana X-5. I have the same J7s on a 2001 Giant NRS, but with 160mm rotors where I have 185s on the Ventana. The Giant is perfectly fine. Both bikes have CK 32 hole rear hubs and all the rotors are the G2 ones.

    I do get a bit of the turkey noise from the front rotor on the Ventana, but I can live with it. Brakes work fine and it isn't terribly annoying (it is mostly at low speed). But, that vibe problem in the back on the X-5 is horrible. I have a set of avid organic pads in there now and it is better but it still vibrates, just not as powerful of a vibe. In the past I tried nylon washers (was on a road/mtb trip so had limited options) on the caliper mount bolts to the frame. Didn't help and have since removed.

    At the end of last week, I swapped to a 160 mm rotor on the back of the X-5. Not much of a change. I have tried all kinds of visual alignments of the caliper to the rotor. No good. Even went with feeler gauges (.008", I think) in between the pads and rotor, applied the brake (all with the caliper bolts loose) and then tightened the caliper bolts. No change...except for one ride..but the ride after that...the vibe was back.

    Maybe if I can find a specialty hardware store at some point (if I was still in San Diego...I know exactly where to go) I can find some rubber washers to try and isolate the caliper mount from the frame somewhat. What I think would be ideal are some thin copper washers with a rubber coating on both sides. I am convinced that for my particular problem that is the only thing that will work with the G2 rotors.

    Someone mentioned trying to calculate the resonant frequencies for different frames....as far as I know, the resonant frequency(ies) is a whole number multiple of the natural frequency of the system. Vibration is usually modeled as a spring-mass system. So, you'd not only need to know the material (to figure out its spring constant), you'd also need to know the cross sectional area (and length) of the tubing for the seat stay. Overall, it is a tough system to model accurately.

    So for a true vibration problem , the easiest method is either to change the systems mass (rotor) or provide some damping (rubber washers). If you look at the method used on cars to stop disc brake squeal (which is a high frequency vibration of the pads), they put some goop on the back of the pads. This changes the mass and adds some dampening to the system as well.

    The turkey noise, problem, at least what I am calling the tukey noise...doesn't feel like a vibration. It feels like I am dragging my brake pads across a cheese grater and there isn't a vibration transmitted through the frame. It was worse with the clean sweep rotors, better with the G2s, but I still periodically get it.

  83. #83
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    Quote Originally Posted by Notorious-J
    I mentioned this above in one of my posts as a possible solution! I am glad to hear it may have solved your particular issue. Please, let us know after further rides in various weather conditions how your situation is evlolving. As somewhat of an amatuer scientist/physicist, I am curious. Logic dictates that if applying your brakes make the frame shudder, the mounting point between the two is the culprit. Afixing some sort of rubber or polyurethane bushing to the mounting point should solve the problem.

    I'll definitely keep you updated on the situation. Like I said, for the one ride I've tried this, my brakes worked perfect WITHOUT the vibration. And I have to agree with your logic that if applying your brakes makes the frame shudder, the mounting point must be the culprit.

  84. #84
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    Yesterday I received my replacement organic pads and rotors from avid, brand new sealed in retail packaging. I'd say that is pretty good customer support. The funny thing is, now that I received the replacement parts my bike just stopped making horrible noises and vibrating. I didn't do anything to it but ride it and it seems better. I can visibly tell that my rear rotor is bent/warped but I'm not going to put the new rotors and organic pads on until I see what happens with the current setup.
    Durango, CO

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    Another possibility I have have come up with is the material of the actual disc. On an automobile the disc is a big, heavy, layered hunk of metal. On a MTB the disc is one peice, thin and pock marked with drilled out holes and grooves weakening over all structure. I know why the holes are there but they may also be part of the problem. I assume most rotors are made of aluminum. Aluminum is notoriously sqeecky because it is a "dirty" metal. You can clean it all day long but a white rag will always come away black. This residue creates a film barrier between the points of contact, the rotor and pads. The film acts as a cooling, but slick, agent that will eventually heat up cause the rotor to warp and change shape on the molecular level. The rapid cooling and heating of thin and flimsy rotor with hydrolic pressures pushing against it will cause the metal to expand and contract quickly causing vibrations that will inevitably start to resonate through the structure on the whole. (the entire bike). I don't know all the materials in question so I cannot prove this but I can suggest a different brake rotor material. Try titanium if its available or cobalt or strontium. At this point, I will blame the aluminum rotor as the faulty component. This is just a theory. Any purchases, good or bad, are your problem.

  86. #86

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    Quote Originally Posted by Notorious-J
    Another possibility I have have come up with is the material of the actual disc. On an automobile the disc is a big, heavy, layered hunk of metal. On a MTB the disc is one peice, thin and pock marked with drilled out holes and grooves weakening over all structure. I know why the holes are there but they may also be part of the problem. I assume most rotors are made of aluminum. Aluminum is notoriously sqeecky because it is a "dirty" metal. You can clean it all day long but a white rag will always come away black. This residue creates a film barrier between the points of contact, the rotor and pads. The film acts as a cooling, but slick, agent that will eventually heat up cause the rotor to warp and change shape on the molecular level. The rapid cooling and heating of thin and flimsy rotor with hydrolic pressures pushing against it will cause the metal to expand and contract quickly causing vibrations that will inevitably start to resonate through the structure on the whole. (the entire bike). I don't know all the materials in question so I cannot prove this but I can suggest a different brake rotor material. Try titanium if its available or cobalt or strontium. At this point, I will blame the aluminum rotor as the faulty component. This is just a theory. Any purchases, good or bad, are your problem.
    So I guess they're steel not aluminum.

    that argument is compelling but how to you explain the magura, hope, hayes, and other juicy rotors, which are made of Steel, and problem free?

    Also the same rotors and pads with the bb7 system seem to be trouble free.

    My new rotors and organic pads are on the way courtesy of Avid.

    I'd like to publicly thank Gear Works Cyclery of Leominster, MA for taking care of the warranty claim even though I didn't buy my bike from them!
    Last edited by johnniewalker85; 07-29-2008 at 05:12 PM.

  87. #87
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    Quote Originally Posted by Notorious-J
    I assume most rotors are made of aluminum. Aluminum is notoriously sqeecky because it is a "dirty" metal. You can clean it all day long but a white rag will always come away black. This residue creates a film barrier between the points of contact, the rotor and pads.
    "As somewhat of an amatuer scientist/physicist" you don't seem to be able to tell one metal from another...or you have never had disk brakes.

    My Avid G2 and Galfer rotors are stainless steel. I bet all but a few specialty rotors are also SS steel.

  88. #88

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    Quote Originally Posted by gmcttr
    "As somewhat of an amatuer scientist/physicist" you don't seem to be able to tell one metal from another...or you have never had disk brakes.

    My Avid G2 and Galfer rotors are stainless steel. I bet all but a few specialty rotors are also SS steel.
    You are absolutely correct. I mentioned in one of my above posts (first one I think, in this thread) that I have never owned or seen up close a set of MTB rotors. From pictures they look like aluminum or steel, so I assumed they were aluminum; the lighter metal.

  89. #89
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    If rotors were aluminum they'd rip right off the rim...

    But I have a quick question... Have they optimized the 08 breaks in any way, or do they also resonate?

  90. #90
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    Quote Originally Posted by Loos
    If rotors were aluminum they'd rip right off the rim...

    But I have a quick question... Have they optimized the 08 breaks in any way, or do they also resonate?
    Someone better tell this guy...
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  91. #91
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    I have just installed my new hope floating rotors (203 front, 183 rear), and the demon turkey seems to have gone!!!! I will give them a real ride tonight, but they feel great just riding around my block. I'll post the final verdict later.

  92. #92
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    Hey guys...I don't have the energy to read 4 pages of thread, but I've figured out the warble on my Avid Juicy 5's.

    When I adjust for pad drag, I loosen the caliper...clamp the lever...tighten the caliper. I looked at the caliper the other day and noticed that there was a part of the finish rubbed off by the rotor. When I looked at the rotor in the caliper...it was not aligned in the center.

    I noticed that one of my pistons was hanging and the other was coming over to compensate for it. It was pushing the rotor into the caliper body causing the "warbling".

    I free'd up the piston and re-centered. All is well.

    It's been 3 years with little-to-no problems...I should consider rebuilding them, he?

  93. #93
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    I just got back from a couple hour ride on my new hope rotors, and they performed brilliantly! There was not a hint of 'turkey', and the power is much greater (i did swap out my 185 rotor for a 203 on the front), plus, they look sweet!

  94. #94
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    Quote Originally Posted by CdaleTony
    Someone better tell this guy...
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    Or MTBR thread
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    My bad, but what about my question?

  95. #95
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    Quote Originally Posted by Loos
    If rotors were aluminum they'd rip right off the rim...

    But I have a quick question... Have they optimized the 08 breaks in any way, or do they also resonate?
    I have Juicy Carbon 08's and they made the turkey noise. I think it's down to the rotors.

  96. #96
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    Organic pads are worth their weight in gold.

    I'd replaced rotors, bled the lines, put in normal replacement pads, adjusted everything 3 times to no avail.

    One set of organic pads are the brakes are now perfect!

  97. #97
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    Two brands of organic pads did nothing for me. It seems to take a different combination for each setup.

  98. #98
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    Here is what I have found:

    I have posted a couple of times. Taking a closer look at my 2 main rides (with the same J7's on them), as well as some pictures from last year of one of my bikes I figured out the difference for me, and it isn't the pads (though they help somewhat).

    I had posted that I never had a vibration problem on my X-5 until I moved back to the west coast. Only an occasional turkey warble. My NRS never had any problems what so ever. I *thought* the only difference was the size in the rotors and the difference in frame design.

    Turns out on my X-5, I have had the old roundagon? rotors at one point. Then the G2 rotors. And now the G2 clean sweep rotors. I have tried both the 160 and 185 mm G2 CS rotors on the back of my X-5, both with organic and semi metallic pads.

    My Giant has only ever had the G2 rotors in 160mm and semi metallic pads. And the only time I didn't have problems on the X-5 was when I was running 185mm G2 rotors (not the G2 CS rotors).

    So, for me, rotor choice is the key. I didn't realize it because I wasn't paying that much attention. But, the G2 CS rotors, you can tell them apart from G2 rotors since the CS rotors are slotted whereas the regular G2 rotors have patterns of three holes drilled in them. I may still try the Galfar rotors since they seem easier to find than the regular G2 rotors.

    FWIW, a friend who rides a heckler with J7s and 185 mm rotors alleviated all of his problems as well by switching to the regular G2 rotors after the roundagon thingys.

  99. #99
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    Quote Originally Posted by gmcttr
    Two brands of organic pads did nothing for me. It seems to take a different combination for each setup.
    The problem is that you cant just put in organic pads with rotors that have already been "bedded in" by metallic pads. If you switch to organic pads to solve the issue, you'll probably need to get brand new rotors as well. Avid sent me two BRAND NEW rotors and sets of organic pads for free, just give them a call...
    Durango, CO

  100. #100
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    The slots radiating around the G1 and G2 rotors are orientated oppositely and the old round-a-gone rotors used holes in place of the slots. My 04 J5's with round-a-gone rotors and my old 04 BB5's with G1 rotors never cried like a turkey. On the other hand, my 07 J5's with G2 rotors vibrate the frame and do the turkey thing. As posted, I have tried (one) 185mm and (2) 160mm rotors, bled the brakes, cleaned the caliper, sanded the OEM semi-metallic pads, cleaned and sanded the rotors and replaced the pads with Avid organics. None of the remedies have worked so it narrows it down to rotors, a design flaw with the caliper or a frame/wheel issue.

  101. #101
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    Update and "solution"
    I tried sanding and cleaning pads and rotors - no luck.
    So I switched pads back to front and rode around the neighborhood. The warble moved to the front.
    As suggested I called Avid and then my LBS and pads/rotor are on the way. Avid said it was a bedding-in problem and since I bought the bike slightly used, and I am a disc brake jong, it certainly could be
    Before yesterday's ride I decided to switch the pads back since I was already used to the warble in the back. Sanded the pads lightly before switching but not as much as I had before.
    Went for a moderately big ride and...
    no noise, no vibration from either brake.

    No this isn't a solution really, but I think someone else "ordered" the new pads from Avid only to have the noise go away. Maybe the stock pads "know" you are giving up on them and decide to starting working. Seems about as likely as some of the other solutions that have worked.

  102. #102
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    An update to what I used to solve my vibration/noise issues.

    I know have 2 rides on my "fix". I completed my first ride without any issues and posted this earlier in the thread. During my second ride...I started to develop the problems again, albeit, not as bad as before. A post ride inspection of my bike revealed that the o-rings I had installed between the frame and caliper adapter, had begun to tear. They're obviously not meant to handle the stress and the torque of tightening the bolts to the specified value. I still believe that MY solution is to isolate the caliper adapter from the frame, I'm just going to have to find stronger material to do so.
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  103. #103
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    With 5 pages under this heading, it seems as this is a design or production flaw that should have been fixed by now. I have had 3 Juicy 5's that have been noise free. The one on the front of my bike now has "chirped" since I bought the bike - through 3 sets of shoes. Usually goes away, but always comes back. It is worse during climbs when you are going slow. Very annoying - may be my last set of Avids.

  104. #104
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    Craig, you need to align your caliper mate. It sounds as though you have a warped rotor, which may be down to you bashing it, or the rotor bolts may need to be tightened. The turkey noise is a completely different beast!

  105. #105
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    My experiences with the Juicy 7 echo so many others on this thread:

    I've had the brakes on 3 different frames and have always had the turkey warble in the rear. I put on the G2 rotors last year hoping for help. Didn't help. This year I put on new Avid organic pads. This helped take care of the turkey warble but now I've got a shudder.

    This rear shudder is awful. Terrible. Makes me not want to use my rear brake. It reverberates up through the saddle, right up my arse and into my spine. Bad news.

    I've tried the extra washers. Didn't help. Tried the toe in trick. Didn't help. Asked 2 good mechanics. Didn't help.

    Basically, I have time to ride/race but not to keep dicking with these brakes. I've really had it.

    And it's really amazing how many on this thread have the same exact scenario/symptoms. It all really makes me like my BB7s on my other bike. Or Formulas or XT brakes.

  106. #106
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    Quote Originally Posted by onbelaydave
    I noticed just a "very" slightly different wear pattern front to back and stuck ~ 3/32" worth of washers under the rear CPS mount and re-aligned as usual.

    The rear is now the quietest, smoothest it has ever felt; better than the front for now. One finger/ 4 oz pressure to lockup/skid the rear tire. I took it out for a short test ride, re-bedding the pads with about 50- 60 stops. Only time will tell.

    Has anyone else had any luck with this? I have a 2008 Fuel EX8 with J5's that just recently develped this in the rear. Was quiet during the ride, but then when I came home and gave it a water shower and rode around the next day it is much more pronunced.

    I assume the washers came from the local home store - lowe's/home depot? What size are the washers? I think this is my problem because i dont have a loud noise at all. Its fairly quiet and more of a feeling...like its hitting the arms - which it is as i can see from the wear marks
    Last edited by jbsmith; 08-05-2008 at 07:38 PM.

  107. #107
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    This is a new problem for my rear J7's - it appears the entire inside pad itself shakes loose enough that the removal tabs actually buzz/scrape against the rotors arms. It doesn't happen all the time, so far seems to be when the weather is cool.

    Anyone have considered going to Juicy Ultimates...would this be an improvement?
    Question to a custom frame builder..."So what makes your bikes climb better?"....his answer, "Uh, your legs?"

  108. #108
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    Quote Originally Posted by jbsmith
    Has anyone else had any luck with this? I have a 2008 Fuel EX8 with J5's that just recently develped this in the rear. Was quiet during the ride, but then when I came home and gave it a water shower and rode around the next day it is much more pronunced.

    I assume the washers came from the local home store - lowe's/home depot? What size are the washers? I think this is my problem because i dont have a loud noise at all. Its fairly quiet and more of a feeling...like its hitting the arms - which it is as i can see from the wear marks
    I just did this for my front and it improved. I got the washers from a spare Avid brake set I have, so it is the same asone that is under the bolt head. I would imagine they could be obtained elsewhere.
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  109. #109
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    Quote Originally Posted by jbsmith
    Has anyone else had any luck with this? I have a 2008 Fuel EX8 with J5's that just recently develped this in the rear. Was quiet during the ride, but then when I came home and gave it a water shower and rode around the next day it is much more pronunced.

    I assume the washers came from the local home store - lowe's/home depot? What size are the washers? I think this is my problem because i dont have a loud noise at all. Its fairly quiet and more of a feeling...like its hitting the arms - which it is as i can see from the wear marks
    I added a washer when I first set mine up. The pads were obviously grabbing the rotor arms and missing on the outside of the rotor. One washer raised the calipers enough to center the pads on the rotor.

    Good luck

  110. #110
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    what if based on the rotor wear it looks like im grabing about 1/8 inch of the arms, but it also looks like it it is geting all of the rotor as well??

  111. #111
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    Any body want to buy some Juicy 7's? If I spend more time trying to fix a problem than I do riding is it really worth it?
    I had a set of old school Hayes Hydro on a Hardtail since 98- and they worked just fine- now these SRAM "newer" and "better" brakes are just a waste of time-

    If I am able to (without losing too much cash) I will remove both sets from my bike and replace them with something that I bolt on and forget about- what a novel idea-

  112. #112
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    I just put two 6mm washers under the CPS system on the rear J5 on my EX8. It seemed to lessen the sound/vibration (i wouldnt call it a vibration - more of a grabby feeling). I rode it up and down the street for about an hour stoping and starting...didnt get worse but not better either.

    I also noticed on the back its impossible to get the rotor to spin without at least grazing one of the pads. I assume this will go away as the pads wear. I also assume that its due to the manufacturing tolerances...nothing is going to be 100% perfect for a 2000$ bike (although it should be!!).

  113. #113
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    Ok I've had the warble problem too. I did something different that I haven't seem everyone else do yet on this post or in other posts. I'll try to explain the best I can...

    I believe the warble comes from uneven pad pressure onto the rotor. When one tightens down the rear caliper, I think everyone loosens the two bolts gently squeezes the rear brake lever until the pads firmly grab the rotor, and then tightens down the two bolts. The caliper/pads are supposed to be self aligning. That is supposed to center the pads correctly and evenly on the rotor. I believe that in that process the centering/aligning is not really happening as it should. Visually, it may look like all is centered, but it really isn't. The loud warbling noise is a testament to this. I believe the caliper is fully grabing the rotor before the tightening of the bolts, but not completely. That is to say that the the caliper/pads actually are at an angle but not clearly visible to the eye but enough to clear the rotor when the wheel turns.

    So...going with that premis I loosened the bolts, then gently squeezed the caliper while holding the caliper with the other hand and helping the pad/caliper alignment process. Making sure that the pads grab the rotor as equally and evenly, as I can possibly can, eye-balling it.

    The resul was, I went from warbling rear brakes consistanly on the descent to no warbling at all on several rides already. Co-incidence? Maybe...maybe not... The only thing that I should have done differently was to sand the pads down evenly. I didn't puposely do that to test my theory. I will now sand the pads lightly as usuall and tighten the calipers as described above as soon as I get a chance.

    In short I really believe the calipers/pads have not really been self aligning. But with some help of the other hand and eyeballing, you can do a better job centering the pads/caliper. I hope some of others can try this if I explained it correctly.

    I can probably test my theory by loosening the caliper again, moving the caliper a bit, then re-tightening it again the old fashion way. But for now, I think I will enjoy some noise free descents.
    If I'm not climbing, I'm not riding.

  114. #114
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    i thought of this as well...it did lessen the issue. I am not sure however if it was eyeballing it or if it was the 2 washers I added.

  115. #115
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    my experience with juicy and the warble has been essentially the offending noise and no decrease in performance. inspeciton of the pads demonstrated them to be badly tattered from dirt and actually filled with specks of metal debris, dirt, grease, etc.

    sanding them down fixed the problem.

    replacing them did as well.

  116. #116
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    Had the same problem for about a year on two different bikes with J7's
    Tried everything mentioned before, new pads, sanding pads, washers etc...

    Then bought a new bike which came with Hayes Strokers and decided to swap the rotors over
    So I have Hayes rotors with the J7's, Avid rotors with the Strokers,
    And for the last 10 months both bikes have worked perfectly and quietly

    Solution is just to change the rotors to a different brand - Hayes rotors work for me

    Fishcake

  117. #117
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    where do you guys get your parts from...such as pads and rotors. After reading fishcakes post i decided to look for a stroker rotor online...of course i couldnt find anything. Is this something where the only option is the LBS?

  118. #118
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  119. #119
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    i have 185 rotors - front and rear...i notice that hayes calls theirs 7'' rotors. Is that just marketing (instead of saying 7.28 inches) or is it really 180mm (actually 7 inches is 177.8mm)? seems to me that the 5mm diffrence shortens the radius of the rotor, thus effectivly raising the caliper - much the same as adding washers under the CPS so the pads arent grabbing the arms.

  120. #120
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    I was having this problem as well. I replaced pads, replaced my avid rotors with new avid rotors (G2), sanded pads and rotors, cleaned pads and... you get the picture.

    What fixed it for me was switching to Hayes rotors. When I switched, as an experiment I replaced my front pads with a new set of sintered Alligator pads and placed new Avid organics on the rear. I had used sets of these same pads with my Avid rotors to no avail, as they continued to squeal, howl, and shudder. This combination with the Hayes rotors however has been silent and smooth.
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  121. #121
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    The problem might be a loose fastened brake cable. Yes you read it right. Make sure to fasten the rear brake cable with cable ties to the frame.
    Try this, it might seem strange and odd, but it works. Not only for me, but several others with the same problem as well.

  122. #122
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    Here is one solution...








    (i've only upgraded the rear for now - as weird as that sounds - since REI only has the 160 (which I only bought since I could use an REI coupon I found online...) ... But after riding it today... Wow!!! I need to get a 185 front somehow soon!!!.... My J5's worked pretty good and I didn't really have much complaint... But the Elixir CR is just so smooth, powerful but with amazing modulation. Installed, adjusted once, and not a peep or squeak out of these on the ride today which had a lot of descents where the brakes were much needed. I'm sure the G3 rotor helped too for quietness (vs the G2).

    On the plus side I sold the J5 rear to a friend who needed a new rear brake... )


    cheers

  123. #123
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    Quote Originally Posted by MI_canuck
    On the plus side I sold the J5 rear to a friend who needed a new rear brake... )
    I hope he doesn't turn into an ex-friend .

    The Elixers look nice. I'm ready to toss the J7s from my Hifi 29er, but I'm not sure about replacing them with another Avid product. I've lost hours this weekend on trying to kill the dreaded turkey, and my faith in Avid is at a low point right now. I am mightily frustrated.

  124. #124
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    There are plenty of other great brake manufacturers out there...

  125. #125
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    Damn, those elixirs look sweet. But, to get back to the Juicy 7 problem..I modified my solution. Previously, I used o-rings between the caliper adapter and frame. Unfortunately, they weren't stout enough to hold up to the stress. Still believing that if I isolated the caliper adapter from the frame, I wouldn't get the resonance vibrations, I took my old adapter from my BB5's which were stock on my bike, installed 2 washers underneath the bolts to hold it to the frame, and also installed 2 washere behind the frame, before the adapter. And viola...quiet as a church mouse. It was so nice to ride and not worry about scaring the local wildlife into running out in front of you on the trail. Not to mention giving women and children a fright whenever I braked behind them. The brakes performed like they did when I first got them, and were so quiet it was unbelievable. I think the fact that my old BB5 adapter is made of different material, and is shaped different, helped change the interaction between the metals, along with the washers isolating it. Don't know if my solution will work for everyone, but it definitely works for me. Incidentally, I'm running 160mm front and rear. Delta Aztec rotors, ebc organic pads in front, and goodridge organic pads in the rear.
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  126. #126
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    Mixing organic and metallic.

    My hifi 29er (juicy 5 brakes) made horrid noise on the rear wheel when breaking. Today the mech. at the LBS told me to try one pad of each. Have only put in a few miles but the noise is a lot less now.

    Will post back in a few weeks to update how this works.

  127. #127
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    Quote Originally Posted by oscarc

    In short I really believe the calipers/pads have not really been self aligning. But with some help of the other hand and eyeballing, you can do a better job centering the pads/caliper. I hope some of others can try this if I explained it correctly.
    I have this problem now with my Codes, but the above statement is absolutely correct. As a bike-shop mechanic for a while, I can attest that when you grab the brake handle, and then tighten the bolts, the caliper TWISTS because of the friction of the bolts as you tighten them. If you are doing this adjustment/setup, watch the caliper VERY carefully and you'll see it. It usually gets "good enough", but I assure you the caliper moves from that "centered" position as you tighten the bolts. Avids CPS is kind of nice, but this is the one problem I have with it vs the old shim method. It was hard to screw up the shim method, but the CPS makes it difficult to get it exactly straight. I have to do some experimenting myself now to try and get it set up so it doesn't reasonate (it's the front brake), but there's a lot of good things to try and ideas in this thread.
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  128. #128
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    Quote Originally Posted by Jayem
    I have this problem now with my Codes, but the above statement is absolutely correct. As a bike-shop mechanic for a while, I can attest that when you grab the brake handle, and then tighten the bolts, the caliper TWISTS because of the friction of the bolts as you tighten them. If you are doing this adjustment/setup, watch the caliper VERY carefully and you'll see it. It usually gets "good enough", but I assure you the caliper moves from that "centered" position as you tighten the bolts. Avids CPS is kind of nice, but this is the one problem I have with it vs the old shim method. It was hard to screw up the shim method, but the CPS makes it difficult to get it exactly straight. I have to do some experimenting myself now to try and get it set up so it doesn't reasonate (it's the front brake), but there's a lot of good things to try and ideas in this thread.
    Holding the lever snug the bolts alternating one to the other till tight this usually does not allow the caliper to shift.
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  129. #129
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    Folks, I believe clearcreek nailed the most widespread cause and solution for the turkey warble problem back on page one.

    I have Juicy Carbons on my '08 Scalpel 2, and while I didn't have the warble noise, I was getting some moderate to severe vibration from the front under hard braking. On my ride today, the front did make a bit of a gobble-gobble sound while braking at one point. I had seen this thread last week and thought to myself, "Oh, great, the turkeys are going to plague my bike."

    Recalling clearcreek's post, I got off the bike, put as much pressure down on the front wheel as I could and executed a few hard stops while shoving the bike backwards. Voila! Vibration gone, and the front is now stopping very smoothly and quietly.

    Since the gobble noise only reared its ugly head once, I can't claim that it is gone, but the vibration was eliminated for the rest of my ride. I will post an update once I've either had a few more trouble-free rides or the problem resurfaces.

    I had to teach myself everything about these brakes since my LBS didn't set them up very well when they built my bike. It was clear to me that they didn't fully understand how they work as they tried to convince me that it was normal to have one lever engage 1/3rd of the way in while the other didn't engage until 2/3rds when they were both adjusted the same. The rear has always worked well and I could get the pads to engage the rotor with the exact lever postion I wanted. The front has been plagued with low-frequency squeal (more of a honking like you'd get with poorly adjusted cantilevers/v-brakes than a shriek like you commonly hear from automotive disc brakes), and too much lever travel was required before the pads would engage the rotor (this was with the lever adjuster set all the way to 'out', which should require less lever travel before engagement). Although the pistons are supposed to automatically adjust themselves to keep the pads close to the rotor, this would not happen, and I would need to pull the lever though about 2/3rds of its travel before the pads would engage the rotor.

    I tried realigning the caliper many, many times to no avail. I went as far as to lubricate the CPS cup and ball washers, being careful not to get any lube anywhere near the rotor or pads, thinking that friction may have been keeping the caliper from aligning properly. No dice. I discovered via an mtbr post that you could force the pistons to adjust inward by removing the caliper from the rotor and squeezing the lever. That indeed did move the pads closer together, however, the caliper would no longer fit over the rotor. I carefully pryed the pads apart just enough to get them over the rotor, but now I could not get the pads to not rub on the rotor no matter how I aligned them. Argh!

    As most of you fully realize, it doesn't take much of a rotor warp to cause you grief, especially if you like your brakes set up like I do: I like the brakes to start doing something after very little lever travel.

    I spent some quality time before my ride today truing the rotor. It takes some patience because you want to bend it little by little, checking it frequently. I could not get it perfect, but I managed to remove roughly half of the side to side warp. This did not help with my lever travel problem, however: I could only keep the pads from rubbing by prying them fully apart before mounting the caliper. This makes some sense since the calipers were designed to work this way. So, I was left with more lever travel before engagement than I wanted, but at least the caliper was centered over the rotor and not rubbing. Off I went on my ride.

    To my delight, about halfway through my ride the pistons adjusted inward on their own and I finally had the feel I had been after since getting my bike. It was a long and frustrating road, which I've now turned into an even longer story, but I hope this will save some people from the frustration I experienced.

    Alignment is crucial, and you are not likely to get it right with a warped rotor. True the rotor, then align. The rest will eventually take care of itself, except, of course, the turkeys. If the turkeys are gobbling at you, try some hard stops in reverse before you go nuts modifying and replacing parts. And for the love of dog, don't go putting rubber parts between your brakes and bike. Your brakes are designed to be rigidly mounted to your bike. Attempting to decouple your brakes from your bike is likely to compromise performance by degrading the feel/modulation, and could even make your problems worse. At best, you're just masking the problem rather than attacking the cause.

    True your rotors and align properly.

    -Pete

  130. #130
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    Update: I had a nice 1.5 hour long, very muddy ride today with some dry stretches and a few good downhills. I enjoyed the pleasure of smooth and quiet brakes the entire time. I know it's only been one full ride since the adjustment mentioned above, but so far it seems to have done the trick. My brakes have never worked better.

    -Pete

  131. #131

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    Interesting fix. That's the same technique some mechanics use to "re-seat" rear drum brakes in cars and light trucks. I guess it works on disc brakes too. Nice going!

  132. #132
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    Good job! Light at the end of the tunnel

    Hi everybody!

    First of all, I must say I’ve not read the thread thoroughly. I’m so damn lazy… Sorry.

    Recently, all my problems disappeared. How? Let me tell you. It’s a very long story (just like everybody else’s, huh?)

    My previous bike was a Specialized Epic, dressed with Juicy 7’s (M.y. 2004) and Mavic Crossmax Enduro. Stock pads, stock rotors, stock hose and stock fluid. Problems: None.

    Not so long ago, I made some money and boosted my ride to a ’08 Yeti 575 (the jewel of the crown). Of course, I reused my reliable (to that day) avid juicy. Amongst a number of operations, the shop that assembled the bike had to refit a new, longer, hose for the REAR brake and, consequently, bled the whole system.

    Beginning of the anguish. Vibration, warble, braking less than adequate. Dozens and dozens of shops “tech guys” scratching their heads, but no solutions after all. Contaminated pads and all that rubbish.

    I dropped stock pads for a set of high quality, and expensive, Kool Stop 270A (aluminum backing plate, you already know). Solved: No way.

    Afterwards, I purchased and tried a new rotor, G2 style -not the old wavy-, to no avail.

    Alignment, realignment, reassembly, cleaning … were not working.

    I started to blame the frameset. All that carbon fiber, no pivots at the dropouts … Finally, I took a stroll to my LBS and ordered a pair of Formula Oro 24’s.

    But I insisted in solving the problem. I had to. Thanks to my mechanical background, I knew I had to mate the frame to caliper bolts with the corresponding washers. First, I used some bakelite washers I had who-knows-where as a leftover. Sadly, they developed a great tendency to fracture. So I have to “upgrade” to stainless steel. I handed a pair of ISO 7089-5 plain washers and tightened the bolts by hand. Plus, as a benefit, the bolts won’t scratch the softer aluminum dropouts. Some people into this thread are suggesting the same; however it didn’t worked for me.

    Also performed the “backwards” re-seating. I was prone to say it didn’t delivered the desired result, but now I’m not so sure about it.

    Now, the mystery. I recalled the banjo fitting on the caliper. I loosened the retaining bolt, turned the ferrule a bit upwards, only to get a smoother bending in the hose. Now, the hose approaches the caliper with a 45 deg angle. Previously, this “angle” was to be notably smaller. Then, retightened the bolt by hand, as usual. (I know, pictures would be really helpful, but I don’t have any at the moment).

    The result of all these procedures put together: No noise, no vibration, powerful and progressive braking… Problem solved.

    No, I can’t explain it either.

    Next morning I phoned the shop and cancelled the order.
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  133. #133
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    I'm not sure about this "backward seating thing". Simply said, the pads go in one way, have the little slot on the back which the piston fits into and your done. It's not like when you put the pads back in to the caliper they need to slip into anything else, by which only the backward force would do it.

    I also don't buy the hose thing, or the sound resonating through the frame. The more I think about it, I seems as though it could be a combination of Avid rotor quality and the caliper not really self adjusting as I described above. The main culprit really being the misalignment of the caliper.

    I bought again, a new set of the Avid organic pads and a new V6 Hayes rotor and installed it last Friday. I was careful to tighten the bolts while holding the caliper level to be sure the pads contact the rotor evenly and at the same time. I really needed a third arm to do this right...but did the best I could. I'm going to try this out tomorrow and see what happens. I'll report back after a few rides though.
    If I'm not climbing, I'm not riding.

  134. #134
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    Quote Originally Posted by Notorious-J
    Interesting fix. That's the same technique some mechanics use to "re-seat" rear drum brakes in cars and light trucks.
    Not sure what you mean by this. I've done rear brakes on most vehicles and was ASE certified at one point. There is no "re-seating" in drum brakes. You install the rear shoes, put the drum back on and adjust the parking brake via the star wheel adjuster. This then sets the distance between the drum and brake shoes. The purpose of backing up in a car and using the brake is that this motion continues to self adjust the parking brake, thus maintaining the correct distance between drum and brake shoes. It is "self adjustuing" via the starwheel adjuster. Some systems work better than others but that is a different story.
    If I'm not climbing, I'm not riding.

  135. #135

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    I don't know if "re-seating" is the correct word to use but I have heard 2 different mechanics doing this. It seemed to work for them, I dunno. I just threw that out there. It's supposed to solve squeaking brakes I think.

  136. #136
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    I changed all of the bolts that mount the caliper to the adapter and the adapter to the frame over to stainless steel bolts and eveything shut up and that was 4 months ago.
    Perhaps they resonate at different requency or something.

  137. #137
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    I still like the resonant frequency idea

    I like the resonance idea..but maybe I am biased since I am currently taking grad class in vibrations

    Well, I got a 160 mm Hope 2 piece rotor today. Threw it on the bike and did a 30 mile ride with some good downhill runs. I'd say that I only had a noise or vibration maybe 2% of the time...and the times I did, the amplitude of the vibration wasn't nearly as bad. That could indicate that with a different spring constant for the 2 piece rotor...the vibrations that occur are now well past the natural frequency of the new rotor and thus the severity (Amplitude) of vibration is much less.

    Or for all practical purposes...perhaps rubbing some chicken bones for good luck helped (or whatever the hell that superstition is with chicken bones)

  138. #138
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    Quote Originally Posted by Notorious-J
    Interesting fix. That's the same technique some mechanics use to "re-seat" rear drum brakes in cars and light trucks. I guess it works on disc brakes too. Nice going!
    Not quite, Beavis. If drum brakes are vibrating, it's because the drums are warped/untrue or the pads are contaminated. Unlike discs, drums don't automatically adjust in the forward direction. Drum brakes are designed to adjust the shoes outward when needed when the vehicle is brought to a complete stop going in reverse. The mechanics you speak of were merely getting the shoes to adjust closer to the drums to achieve stronger braking and a better pedal feel - this would have little to no effect on any noise or vibration. The reason it sometimes takes a mechanic to do this is because most folks don't understand how drum brakes work, and seldom, if ever come to a full stop in reverse (if you watch you'll see most people inadvertently use the transmission to stop the car and get it moving forward). Also, the star wheels that are responsible for adjusting the shoes outward towards the drum can be a little stubborn, so sometimes several hard stops in a row in reverse are required to restore nomal braking and pedal feel.

    All that having been said, the turkeys reared their ugly heads again while I was on my ride today. Unlike all past rides, it was a beautiful, very dry (no humidity) day today here in NH. The turkeys were quite fleeting, only appearing a few of times over the course of 1.5 hours, and any vibration that accompanied them was minor. The two or three times it happened, hard stops in reverse made it go away for awhile. My front rotor could still be slightly more true than it is, although I imagine it's well within design spec. I can't claim my caliper alignment is spot on, but it must be reasonably close since I'm getting excellent power and modulation, and the pads are quite close to the rotor with no drag/contact.

    My next move will be to bevel/round the leading edge of the pads slightly, since if the leading edge is square and makes contact before the rest of the pad, vibration and noise is inevitable. Of course, pulling the caliper to tweak the pads will naturally cause the caliper to be at least slightly realigned when it is reinstalled, so this experiment does not really have the potential to lead to an exact cause.

    BTW, any time brakes are making noise, at least one component is going into resonance (most likely the rotor in this case). When vibration is felt, typically a component or set of components with more mass than the rotor has gone into resonance. In the absence of a resonant condition, you are not likely to hear any noise or feel vibration, and this is because at resonance forces grow by at least an order of magnitude whereas the effects of non-resonant vibration tend to be much more linear. This is one of the major reasons these brake noise/vibration problems can be so fleeting: they're dependent on the bike speed as well as the braking force involved.

    I'll post an update once I've played with the front brake some more. For now I'm not too worried since I have excellent braking power and feel, and the birds visit very infrequently and are easy to shoo away.

    -Pete
    I can barely get my mouth around it.

  139. #139
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    An update from my posts #'s 40 and 75.

    I now have about 240 miles with the Galfer rotor and pad combination (Juicy 7's) and still no noise.

  140. #140
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    What about solutions for those who dont want to spend $$$ on new rotors? Ive tried cleaning and sanding but have not gotten the noise to go away. When i get the bike over to the LBS ill have them do some adjustments and see if that works, if not i will be putting organic pads and seeing if that changes anything...

    Ill keep everyone posted.
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  141. #141
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    Quote Originally Posted by PimpinD
    What about solutions for those who dont want to spend $$$ on new rotors? Ive tried cleaning and sanding but have not gotten the noise to go away. When i get the bike over to the LBS ill have them do some adjustments and see if that works, if not i will be putting organic pads and seeing if that changes anything...

    Ill keep everyone posted.
    In the absence of a contaminated pad, defective pad (not likely, but all manufacturing processes have some percentage of defects), or defective rotor, I believe caliper alignment/centering is the prime culprit for the type of vibration that can bring the turkeys out.

    It could be that with the stock pad/rotor combination, the system is very sensitive to being anything other than perfectly centered. This, of course, would be exacerbated by the slightest rotor warp. The very, very slight rotor warp that I have on the front is why I believe I have an intermittent turkey problem on the front and not the rear.

    I did manage to straighten out the rotor a bit more last night, to the point where I think it's about as straight as a human might be able to get it. I'll realign the caliper once more before taking a ride tomrrow and post an update (now the the rotor is a bit more true, the caliper may not longer be centered on the rotor, thus the realignment).

    -Pete
    I can barely get my mouth around it.

  142. #142

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    Quote Originally Posted by Pedalphile
    Not quite, Beavis. If drum brakes are vibrating, it's because the drums are warped/untrue or the pads are contaminated. Unlike discs, drums don't automatically adjust in the forward direction. Drum brakes are designed to adjust the shoes outward when needed when the vehicle is brought to a complete stop going in reverse. The mechanics you speak of were merely getting the shoes to adjust closer to the drums to achieve stronger braking and a better pedal feel - this would have little to no effect on any noise or vibration. The reason it sometimes takes a mechanic to do this is because most folks don't understand how drum brakes work, and seldom, if ever come to a full stop in reverse (if you watch you'll see most people inadvertently use the transmission to stop the car and get it moving forward). Also, the star wheels that are responsible for adjusting the shoes outward towards the drum can be a little stubborn, so sometimes several hard stops in a row in reverse are required to restore nomal braking and pedal feel.
    -Pete
    Well then I guess I stand corrected, init? There's no reason for name calling, Butthead.

  143. #143
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    Pete - What technique are you using to true your rotor?

  144. #144
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    Quote Originally Posted by PimpinD
    What about solutions for those who dont want to spend $$$ on new rotors? Ive tried cleaning and sanding but have not gotten the noise to go away.
    If there is anything that you should learn from these 6 pages of posts (and all previous posts about noisy disk brakes by all of the manufacturers), it is that each of us has to experiment with our own particular setup to learn what will work for us.

    You start with the freebies (align, clean, sand, bevel leading edge, etc.). If they don't work, you start spending $'s...pads first and if that doesn't work, different rotors.

    I have seen the owners of other brands say Avids are junk, but this forum has had several Hayes, Formula and Hope owners aksing how to cure their problems lately. It happens across all or at least most brands.

    OK...I'm done now.

  145. #145
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    I have given up!

    I can sympathize with you guys. So far I have spent countless hours trying everything, not only what I have read on here but what some of my friends have suggested and have come up with nothing. I hava also spent about $400.00 on different parts, ie rotors (3 different manufactures) all sizes (160, 185, 203), 5 different types of pads (all different manufactures). I can honestly say that I have done EVERYTHING to try and resolve the horrible vibration during the descent.

    The best solution I found to fix the problem was to order a set of Formula Oro Puro brakes and throw in the towel. If I had just bought them when this started I would have an extra $400.00 to buy some hubs with.

    Anybody want to but a set of slightly used TURKEY brakes? GOBBLE GOBBLE!!! (Junky fives)


  146. #146
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    Quote Originally Posted by SAR13
    Pete - What technique are you using to true your rotor?
    Bare hands, my friend.

    I do either put a paper towel over the rotor or wear clean gloves so that I can check it often without cleaning the rotor. You don't want finger oils contaminating the pads. I check the rotor by spinning the wheel and watching the rotor pass between the pads very carefully - despite the tight clearance, it's tough to see the warp.

    As for my bare hand technique, if the warped section is on the side facing me and needs to be bent away, I'll get the section needing adjustment at the top. I'll then grab it with an overhand grip, so that the fingers on both my hands are over the top and grabbing onto the back side. I then use both thumbs to push the section away from me as I pull towards me with my fingers. It's important that you keep the overall force on the rotor neutral, else you may end up straightening a small section only to create a new warp over a larger section.

    Start slow with little pressure and check often....that way you'll be applying the minimum amount of force to get the job done. I imagine it wouldn't be that difficult to make things worse if you try to hurry the process.

    Of course, this is what I've done for a slight warp. If you've got a more severe warp, a more radical approach or tools may be needed.

    -Pete
    I can barely get my mouth around it.

  147. #147
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    I had Juicy 5's then 7's and both were warblin like it was Xmas every ride


    Bought a set of Formula Oro Bianco's, a completely different kettle of fish - far more braking power, lots more modulation, no rubbing and awkard setup and NO warbling!

    Formula for the WIN!

    My dead avids going back for a refund




    Worlds apart






    as a side thought the shiny material Formula use for the brake mounts as in above pic feels like under extreme force it could be slightly shock absorbant - reducing the "turkey judder" to zero?
    i can't ride for sh*t but i'm good at extreme pushing

  148. #148
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    Quote Originally Posted by PatrickOrtega
    Hi everybody!

    First of all, I must say I’ve not read the thread thoroughly. I’m so damn lazy… Sorry.

    Recently, all my problems disappeared. How? Let me tell you. It’s a very long story (just like everybody else’s, huh?)

    My previous bike was a Specialized Epic, dressed with Juicy 7’s (M.y. 2004) and Mavic Crossmax Enduro. Stock pads, stock rotors, stock hose and stock fluid. Problems: None.

    Not so long ago, I made some money and boosted my ride to a ’08 Yeti 575 (the jewel of the crown). Of course, I reused my reliable (to that day) avid juicy. Amongst a number of operations, the shop that assembled the bike had to refit a new, longer, hose for the REAR brake and, consequently, bled the whole system.

    Beginning of the anguish. Vibration, warble, braking less than adequate. Dozens and dozens of shops “tech guys” scratching their heads, but no solutions after all. Contaminated pads and all that rubbish.

    I dropped stock pads for a set of high quality, and expensive, Kool Stop 270A (aluminum backing plate, you already know). Solved: No way.

    Afterwards, I purchased and tried a new rotor, G2 style -not the old wavy-, to no avail.

    Alignment, realignment, reassembly, cleaning … were not working.

    I started to blame the frameset. All that carbon fiber, no pivots at the dropouts … Finally, I took a stroll to my LBS and ordered a pair of Formula Oro 24’s.

    But I insisted in solving the problem. I had to. Thanks to my mechanical background, I knew I had to mate the frame to caliper bolts with the corresponding washers. First, I used some bakelite washers I had who-knows-where as a leftover. Sadly, they developed a great tendency to fracture. So I have to “upgrade” to stainless steel. I handed a pair of ISO 7089-5 plain washers and tightened the bolts by hand. Plus, as a benefit, the bolts won’t scratch the softer aluminum dropouts. Some people into this thread are suggesting the same; however it didn’t worked for me.

    Also performed the “backwards” re-seating. I was prone to say it didn’t delivered the desired result, but now I’m not so sure about it.

    Now, the mystery. I recalled the banjo fitting on the caliper. I loosened the retaining bolt, turned the ferrule a bit upwards, only to get a smoother bending in the hose. Now, the hose approaches the caliper with a 45 deg angle. Previously, this “angle” was to be notably smaller. Then, retightened the bolt by hand, as usual. (I know, pictures would be really helpful, but I don’t have any at the moment).

    The result of all these procedures put together: No noise, no vibration, powerful and progressive braking… Problem solved.

    No, I can’t explain it either.

    Next morning I phoned the shop and cancelled the order.


    You should have kept them on order because it will be back. I had some of the fixes I did last 3 to 4 good rides, just enough time to start thinking it was gone, then BAM the TURKEY was back. Seriously though it will come back, trust me.

  149. #149
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    Quote Originally Posted by Pedalphile
    Bare hands, my friend.

    I do either put a paper towel over the rotor or wear clean gloves so that I can check it often without cleaning the rotor. You don't want finger oils contaminating the pads. I check the rotor by spinning the wheel and watching the rotor pass between the pads very carefully - despite the tight clearance, it's tough to see the warp.
    I use a large monkey wrench, fits nicely.
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  150. #150
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    Quote Originally Posted by gmcttr
    An update from my posts #'s 40 and 75.

    I now have about 240 miles with the Galfer rotor and pad combination (Juicy 7's) and still no noise.
    Galfer rocks!!!!!
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  151. #151

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    those formula's are lookin' goood.

    i'm convinced its the crappy avid clean sweep rotor. i had the CS 160 on the rear and it made noise even when my juicy 5's weren't on... switched the rear to shimano 160 with my XT's and it works great!

  152. #152
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    Quote Originally Posted by nick59349
    You should have kept them on order because it will be back. I had some of the fixes I did last 3 to 4 good rides, just enough time to start thinking it was gone, then BAM the TURKEY was back. Seriously though it will come back, trust me.
    Yeah, sadly, that is exactly what I think is going to happen sooner or later. Who knows? May be I'm the first that suceeds where others have failed. Pretty snooty, huh?

    No, no way. Eventually, it will come back. Of that i'm sure. Thanks for the advice, friend.
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  153. #153
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    Quote Originally Posted by newpos
    those formula's are lookin' goood.

    i'm convinced its the crappy avid clean sweep rotor. i had the CS 160 on the rear and it made noise even when my juicy 5's weren't on... switched the rear to shimano 160 with my XT's and it works great!

    I tried two other manufacturers rotor and if anything they made it worse.

  154. #154
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    rode my HiFi with the Elixir CR's last night and much quieter - i suspect a part of this due to the G3 rotor (vs the G2 i had with the J5's)... pads are the same material - sintered metallic (although Elixir and Juicy pads are different in shape)... But so far very satisfied with the Elixir CR upgrade

    under cornering while braking (so a lot of side load), still got the odd squeak... thanks to the 9mm QR front and rear, and the HiFi not having the stiffest rear dropout in the world, flex plays a part in noise...

    the solution for anyone most likely won't lie in a single fix... it's a system approach...

  155. #155
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    Quote Originally Posted by MI_canuck
    flex plays a part in noise... .

    That is what I though as well, but the stiffer the rotor I tried the worse it got.

  156. #156
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    Quote Originally Posted by nick59349
    That is what I though as well, but the stiffer the rotor I tried the worse it got.
    i meant more in frame/axle mount stiffness... if there any amount even 0.0005" between axle and frame (ie. quick release axles), there will be relative motion between rotor and caliper...

  157. #157
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    As previously posted, my rear 07 J5 with either a 185mm and 160mm clean sweep G2 rotor mounted to the wheel screams like a turkey in heat and vibrates the back end of my bike. Switching from the OEM semi-metallic pads to Avid's organic pads helped resolve the issues until they bedded in. Sanding the pads fixes the problem until they bed in again. Using a old 160mm round-a-gone rotor fixed the vibration problem (for 4 rides) and changed the frequency of the turkey warble to a more tolerable level. What is interesting is that the front caliper with a 185mm CS G2 rotor never makes the turkey warble sound or vibrates. I wonder if the front is problem free because of A) the caliper is oriented in a vertical position, B) the fork’s mounting tabs are casted to a much tighter ISO tolerance than the bike frame’s tabs or C) that the newer frames have much stiffer/rigid caliper mounting tabs that transmit any brake vibration through the entire bike frame, which amplifies the effect.

    My newer 07 Specialized Stumpjumper FSR frame has very beefy (large diameter) chain stays and seat stay tubes with the ISO caliper tabs welded directly to the top of the seat stay. To my eyes this setup looks very strong and rigid. My old 04 SJ FSR ISO caliper tabs were a good inch above the seat stay tube and utilized thin aluminum bars to tie them into the seat stay tube. I could easily move the caliper side to side because the ISO mounting tabs were so thin and flexy. However, I never experience any vibration or turkey warble sounds from my 04 J5 brakes in over three years of riding. My 07 SJ with 07 J5’s vibrated after three rides, which points to the frame as the culprit of the problem.

  158. #158
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    Quote Originally Posted by bwalton
    I wonder if the front is problem free because of A) the caliper is oriented in a vertical position, B) the fork’s mounting tabs are casted to a much tighter ISO tolerance than the bike frame’s tabs or C) that the newer frames have much stiffer/rigid caliper mounting tabs that transmit any brake vibration through the entire bike frame, which amplifies the effect.
    While I believe all three of these could affect the nature of the symptoms, in some caes making the symptoms tolerable, I believe the root cause is still excessive vibration at the pad/rotor interface.

    The hubs and wheelset are another factor that could have significant effects on the symptoms. The fact is, though, disc brakes should not vibrate noticeably when they are working properly.

    I'm still getting the occasional warble on the front of my bike. Pushing the bike backwards into a hard stop makes it go away 100% of the time, but only temporarily.

    I'm starting to wonder if the stock Avid pad backing plates are a contributor to the problem, since they are responsible for the pad/caliper interface. Ideally the pads would seat in the caliper and not move around enough to have negative effects on braking, but the 100% success rate of the temporary fix described above would suggest that is not happening.

    Some folks have had succcess switching to Avid's organic pads - has anyone compared the backing plate on those to the stock pads?

    -Pete
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  159. #159
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    Quote Originally Posted by Pedalphile
    ... I'm starting to wonder if the stock Avid pad backing plates are a contributor to the problem, since they are responsible for the pad/caliper interface. Ideally the pads would seat in the caliper and not move around enough to have negative effects on braking, but the 100% success rate of the temporary fix described above would suggest that is not happening.
    ...
    Most of us aren't even using avid pads, whatever the replacement may be: EBC, Kool Stop, Galfer... And that remedy hasn't worked in most cases.

    Simply put, the pads are not the origin of the problem by themselves, and for sure 'organic flavor' is not a solution. I'm sorry.

    Have a nice day.
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  160. #160
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    I removed the thin shim washers between the bottom of the CPS cup and the top of the adapter yesterday and discovered two things: 1) The round-a-gone rotor doesn’t randomly chirp like the G2/CS rotor does without the shim washers. 2) The turkey warble is almost indiscernible using the round-a-gone rotor without the shim washers. I also packed the ISO disc tabs on the frame with grease to help dampen any vibration. So for me the rotor seems to play the largest roll in how my rear brake resonates.

  161. #161
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    Well i seemed to have a solution to my noise issue.

    I purchased these organic brakes from blueskycycling.com
    http://www.blueskycycling.com/produc...s_for_Avid.htm

    installed them today and took it for a spin around the block, no noise. I wont be able to full test them till tomorrow on my ride to work....
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  162. #162
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    Seems like the "trend" is that people do this...ride around the block...bike works fine...they post a "solution"...3-4 rides later, problem is back.

    Let us know if it really works after a couple hundred miles or so.

  163. #163
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    will do! end of the week then
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  164. #164
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    Quote Originally Posted by PimpinD
    will do! end of the week then
    Animal

  165. #165
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    I rode my juicy 7's three times...it got worse each time I did a bit of research and read this thread and others...I bought a different brand. I am not going to chase it down and constantly fix it. It really ruins a good ride, with the noise and vibration...I took a loss, but will enjoy my next ride for sure....

  166. #166
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    well my noise wasnt AWFUL, and i didnt really get the vibration... looking at my old pads they had nice gashes in them which might have been causing it... ill know tomorrow after my ride to work where i can usually make the noise show up on command if the issue is gone or not...
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  167. #167
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    I changed my front 7" G2 rotor back to a 6" first Generation or G1 rotor. Noise is gone, pulsation is gone...though this was just a "round-the-block" test as well.

    I expect my problem will be gone when I:
    a. change rotors to something that doesn't have a varied edge like a smooth XT rotor
    b. buy some code 5's, hahaha.

  168. #168
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    well i rode to work this morning, 3miles in the humid FL climate, no noise. Im still breaking in the pads, but for now im content. Ill keep everyone posted.
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  169. #169
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    So far 3 rides...

    All 3 rides have long descents, some sandy, dusty conditions. Some steep sections. In my last effort, I installed a V6 Hayes rotor, yet another set of organic pads. I used alcohol to clean the rotor as per the Hayes directions. Then I tried to carefully align the caliper as I tightened the bolts as I have previously described.

    The first ride/descent (20 minute descent) I just could hear the nice clean friction sound of new pads and rotor. After the ride, I noticed that the markings on the rotor from braking appeared to be somewhat streaked, some dark shades as if the contact between the pad and rotor was not complete. Shading maybe from heat, maybe dark from heat because there was more friction on those parts??? Could it be that the new pads are not completely flat? At least I had no loud noise but I guess with new parts, that was expected.

    On the second ride, I still did not have the turkey noise but did develop an intermitant squeaking noise from rotor rub which depended on the speed of the tire rotation. After the ride I did notice more of the brown tint, apparently from heat? Although I would have expected for evidence of heat to show up as a blue color, like on a vehicle brake rotor. I attempted to realign my rear caliper before my next and third ride.

    Yesterday, on the third ride, I began to start to hear some more noise beginning. Now the noise was beginning to sound like the howling, moaning coming back. On this descent however there we're stops and I believe time for the rotor to cool down. That may have contributed to the noise not completely coming back. After the ride, I noticed some of the brown shading was gone but there were still some brown streaks around the rotor. Later that day I decided to lightly hose my bike off with water and relube things. After I relubed my chain, and turning the crank while the rear was off the ground, I applied the rear brake and got the howling!...I continued to spin the rear wheel off the ground and when I lightly applied the rear brake, the howl was there. Only if I applied faster, harder pressure, did the brakes not howl. I'm curious had the descent been longer, as to generate more heat, whether the howling would have been back.

    My next step will be to once again, remove the pads and sand them down lighting on a flat surface, go out and ride again and see what happens. The saga continues.

    Guess I'll report back later...
    Last edited by oscarc; 08-25-2008 at 10:17 AM.
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  170. #170
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    I thought the organic pads and new rotors fixed if for my J5, but it came back. This time, though, the caliper had loosened a bit. Tightening it didn't solve the problem, though. It only helped it to be a bit quieter is all.

    Since my XTR brakes have always worked fine on my other bike, I just found a used set of xtrs and made the switch. They work silently, but when aligning the rear caliper I found that I needed one extra shim between the frame mount and the caliper on one of the 2 bolts. Seems that the ISO tab on the frame is just a slight bit off. Now, with the J5s, I'd aligned the caliper perfectly, I thought, so I didn't think this was the issue. But, in any case, the xtr brakes are fine so far.

    I don't see it being the frame in my case, since the problem seemed to go away for awhile after changing pads and rotors. But, at this point, I found the solution. New brakes. No more avids for me.

  171. #171
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    I know this is a juicy thread, but what about these style of breaks - Hayes HMX-4 Mechanical Disc Brakes w/ 6″ Rotors. I have a noise coming from the back break? still reading through the pages here to see if there is a fix, but thought I would see what you have to say.

  172. #172
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    OK...I've been in the same situation as most of you w/ this brake issue (2008 Juicy Carbon). I think I've had it in all its forms: slight low-frequency buzzing all the way through crazy and violent shuddering and vibration through the seat/frame. I've tried many things; re-aligning CPS bolts, sanding pads, cleaning pads with acetone and rubbing alcohol, etc. However, I think I've got it! (at least for my situation). I think its a problem, like one person mentioned, with the self-adjusting pistons not actually self-adjusting properly (and engaging the disc with slightly different pressures). In other words, I made sure to push both pistons completely back into their bores, and then made sure that they were flush all the way around. (make sure you don't destroy the pistons at this point, because it may take a bit of pressure to push them back in) Prior to doing this, I did notice that one piston (in its 'rest' position) was further extended towards the center of the caliper than the other. After pushing them both back in and then putting things back together, both pistons' 'resting positions' are equal. I've ridden my bike for probably 50 miles (over 3 different days) since, with tons of braking and various usage scenarios and things are very SWEET and silent! Let me know if this helps-I know it seems kind of obvious, so I'm guessing some of you have tried this already. Let me know if this helps or works for you...
    Happy riding~

  173. #173

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    I read somewhere that replacing the pads with organic ones, fixes the problem for most people. Can anyone confirm this?

    I only had my bike for 4 months and ride once a week? Should I change the pads now or should I wait and see if the noise clears away eventualy?

  174. #174
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    pfeng - i think you nailed it. I made sure my pistons were back in place properly before installing the new pads. So far im 15miles in of riding, and where id normally get the noise its still silent. Usually leaving work, my bike is stored indoors in the A/C... the minute i roll it outside, its covered in condensation (got to love FL). The bike would make make all sorts of noise because of this... but yesterday same deal, nothing differnet... ill keep trying it and maybe find some left over Fay puddles and ride through them and see if i can get them to make any noise. If i pass 100 miles with no noise ill assume the issue is solved =P...
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  175. #175
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    Avid Organics + new rotor = same problem

    No luck with the Avide recommended swap to organic pads and the new rotor (Clean Sweep 3).

    Next step will be the Hayes rotor.

    If that does not work - Formula K24s.

  176. #176
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    FAIL! =(

    The vibrations have slightly come back. I will be taking it to the shop to have them adjust the brakes one last time with the new pads (maybe i messed up the alignment) and if not ill just give up lol
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  177. #177
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    Quote Originally Posted by PimpinD
    FAIL! =(

    The vibrations have slightly come back. I will be taking it to the shop to have them adjust the brakes one last time with the new pads (maybe i messed up the alignment) and if not ill just give up lol
    What a pity! Keep trying...
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  178. #178

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    I did the whole organic pad thing and that didn't work..... I just switched to the new 08 XT system so the Juicy 7's are officially for sale.

    They came stock on my 07 Stumpjumper FSR Expert.

    Good luck to those who keep trying.... you have more patience than me. After following this thread I decided I would switch to a new system once something came up... sure enough some squealing, vibrating and pulsating/shuttering began in the rear so I wasn't even going to begin trying to fix it.

    For the record the front was always flawless for me and they are very powerful if you can ignore the problems.

    Sad!
    Last edited by Sopranos; 08-26-2008 at 05:09 PM.

  179. #179
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    yea i dont have the cash to throw on a new set of brakes just yet, so in the mean time i will continue to tinker...
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  180. #180
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    I switched front rotors and went for a ride today. My issue is resolved for the front. Rear is still gobble-gobble.

    I'm gonna swap the front and rear and see if it changes things.

    Mine were fine for 2 years. All the sudden, they started to crap out.

  181. #181
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    the brakes must read this forum also! they know when we are talkin about them!
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  182. #182
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    Reading all of this mega-thread and having been bit by the turkeys myself, I'm beginning to suspect that the caliper itself could potentially be the problem.

    -Pete
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  183. #183

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    I still have no fix. I have a new set of avid rotors and pads sitting in my room, but I haven't had time to put them on and go riding. Chances are it will fix the problems until they pads bed in. Avid seemed to think I hadn't bedded them in properly when I called them. I did some some medium to slow stops to bed them in. It's not like I went did some downhill at Mt. Snow the first day i bought the bike.

    I short. No fix yet. I don't have the money to buy new brakes. Unless I can get some from work at cost.

  184. #184
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    I had this issue a couple years ago with my J5's. I ended up shimming the caliper up because the pads were hitting the rotor arms. Been quiet ever since.

    However, I have BB7's on my new bike and the front squeals like a pig. I road with a group of 5 the other day all had avids except for one. It was like a boys choir rolling through the woods. Everyones avids were either squealing or warbling.

  185. #185
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    I got bit by the turkeys. I changed to Kool Stop pads and they stayed away for a month or so. Then I started getting the turkey and non-retraction of the front caliper. Juicy 7s were my first hydraulic brake. I almost went back to BB7s, but now I really love my Formulas . . . no trouble at all with K24s or Puros.

  186. #186
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    I may have found the problem!!!

    I have noticed an inconsistancy with pads. I went 2 years ( I think) without the warble. I changed to a new set of EBC Green pads which is the same that I've been running for the past 2 years. I noticed that the new pads grab lower on the rotors. The pad material is actually molded to the backing plate about 1mm lower than my previous set of EBC's.

    I know you say "how can you see 1mm", but I look at EKG's all day and can eyeball a mm or so with confidence.

    I noticed the same thing on my new set of Kool Stop pads that warbled and shuddered. I just switched front rotors from my 7" to 6" and it "cured" the front rotor noise and shutter. What I noticed was that the pads contact on the 6" rotor left about 1mm of rotor below the edge of the pad.

    My rear brake actually grabs low on the rotor hanging about 1/2mm below the edge of the rotor. The shutter feels like it's happening about every time a rotor spoke goes by. It's too fast for it to be happening every time a rotor vent goes by.

    I put some thin washers on my rear caliper to place it outward on the rotor with about 1/2mm of rotor hanging below the edge of the pad. I'll see if this works okay.


    If it fixes the problem, I will put my 7" front back on and shim it out 1/2mm to 1mm and see if it cures the front issue.



    Look at the lower (proximal to axle) edge of your pads in relation to your rotors and see if the pad hangs below the edge of the rotor at all. I believe that "any" overhang will cause the problem no matter how tiny, so I think the fix is to make sure that the rotor slightly rests below the pad.


    This would explain the inconsistancy with occurances too. With new pads and new rotors, the surface of the pad will need to wear down a bit before the lower edge of the pad starts to grab on the rotor spokes.


    I'll keep you posted.

  187. #187
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    Lots of people have tried washers already including me.
    From the markings on the rotor it is clear i already have a couple mm clearance from the bottom of the rotor arms.

    What I have noticed is that even brand new rotors from Avid were not true out of the packaging.
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  188. #188
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    I wonder if avid will ever fess up and replace the deffective parts, if we can ever figure out what is exactly causing it. When i talked to avid, they the brakes are noisy.
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  189. #189
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    Quote Originally Posted by bbgobie
    Lots of people have tried washers already including me.
    From the markings on the rotor it is clear i already have a couple mm clearance from the bottom of the rotor arms.

    What I have noticed is that even brand new rotors from Avid were not true out of the packaging.

    It seems to have been the right cure for post #184...Oh the inconsistancy.

  190. #190
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    8 pages of people having major trouble with Avid brakes, I’m loving this, especially when I think back and remember that people didn’t believe me when I said what awful brakes they are and how many problems I had had with them about 8months ago.

    Good luck people, I binned mine in the end and got some XT’s, they were no better so I binned them too and now have 2 sets of Hayes Stroker’s running perfectly so there is light at the end of the tunnel.

  191. #191

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    Quote Originally Posted by PimpinD
    I wonder if avid will ever fess up and replace the deffective parts, if we can ever figure out what is exactly causing it. When i talked to avid, they the brakes are noisy.
    Wouldn't that be nice. They sent me new rotors and pads when I had my LBS call them, but the wouldn't admit to any problems with the brakes. I won't be buying any Avid hydraulic brakes in the future.

  192. #192
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    re: Avid Warranty

    My local bike shop (yeah Mojo Wheels!!!) is trying to replace the whole brake system for me right now. I will keep everyone posted on the result.

    We have tried replacing pads, rotors, etc. Still vibrates like crazy. Note: I say vibrate - not just make noise. There is a huge annoying and scary difference.

    Apparently, Avid is fully aware of the problem and willing to replace the system but only if all other options are exhausted, as they have been in my case.

    I am glad that this is now an option but, frankly, am so put off by Avid's poor response to this that I will probably switch the brakes out for Formula k24's or the new XT.

    I did a search on problems with Formula brakes and found one small forum thread from another site and the formula customer service department responded to that thread immediately with helpful advice. Has anyone seen a post from Avid here on this thread offering to help or clear the air???

  193. #193
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    I just said f'it and picked up a set of Hayes Stroker Carbon with V6 rotors new for $295 shipped. Cant complain, i hope they are quiet =P
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    Hifi => Ex 9. Thank you warranty.

  194. #194
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    Don’t get the new XT’s, I got the same problems with them, at least the Avid’s had a decent amount of power to go with the millions of problems.

    Formula’s are well known to be the safest bet…

  195. #195
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    what are the XT's?

    I rode my friends Trance with Stroker Trails, and they were powerful and quiet. I expect them same if not better performance from the Stroker Carbons.
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  196. #196
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    I had turkey gobble to start with on the Stroker’s but it went away after a bit of use. The XT’s just kept getting worse and worse and worse even after cleaning the discs/pads repeatedly and replacing the pads front and back 5 times. The pads are also very easily contaminated even with the sintered pads. Power is minimalistic even when working fine, the brakes do not work with other mineral oils which I find a bit strange and I think myself, 3 bikes shops and Shimano all tried and failed to bleed them to a usable state over 10 times. So all in all I was not happy with XT’s and just because Shimano couldn’t find the problem they argued there wasn’t one even though they clearly don’t work.
    Last edited by EGF168; 08-27-2008 at 01:58 PM.

  197. #197
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    Ok guys, bare with me...

    Go back and read my post #113 then come back...

    Ok, yesterday night I sat myself down right in front of my rear brakes and looked and stared at them for about 15-20 minutes. No adjusting, pulling out pad, sanding or anything just looking at them, from sides, top, lifthing the bike to view from the bottom, you get the picture...If you read my post #113, I believe that when engaging the brakes, the pads are not in full contact with the rotor. Hence, the noise is coming from the rotor, not the caliper, frame, pads or anything else. In short, the caliper is not really aligned.

    So...after really focusing on my brakes I began noticing that if I looked at my brakes from behind the rear wheel, looking so that I can see the caliper up on top, allen bolt top to bottom, you see allen head, then the small steel washer, the little cupped spacer, and the longer spacer in which the cupped spacer fits into. Then you have the caliper bracket, then another cupped spacer, then another long spacer, then the caliper bracket itself. Hopefully you get the picture. The bolt of course fits through all these and into the bracket. I believe that the caliper bolts should both be perfectly aligned top to bottom. When I look at bolts and washers top to bottom, the bolt from behind seems to be angled into the wheel along with the washers. Further more the washers are also not aligned and the little cupped washers are not even. What I mean by not even is that when I look around the edge of the cupped washers, there is more space around one side then there is on another. So in short, the stack of washers along with the caliper seem to be leaning into the rear wheel. To me this is out of alignment. Meaning the whole body, not the pistons. In my mind this leaning is causing uneven contact resulting in noise. When looking from behind and applying the breaks, I can now see the pads beginning to touch unevenly and the caliper then starts to lean also. I can also see the rotor deflecting to compesate for the pads. The pads to now show uneven wear, especially where the material seems to be taking more heat and more pressure. I can see where the pad almost appear to be crushed a little from the pressure. There is wear I believe the noise is coming from.

    Now, how to fix? I'm not sure. I would think the cupped washers for one need to go and replaced with flat washers which I don't know where to find substitutes. I'm not sure what kind of fix to undertake here now...

    Another note, the Avid Juicy 7 caliper body has those slots which to me also offer more slack. I know the slots and cupped washers are clearly designed that way to "self adjust". The problem though is that all this seems to be causing the whole caliper to lean inward unevenly.

    So...can anyone provide me the phone # to Avid? I haven't been able to find it on there website. I plan on calling before go out and buy some Hayes or something else.

    Also, a question for those who know. When comparing the caliper body bolt holes to other brands, are the other brands also slotted?
    What about spacers and washers, what do those look like in comparison to Avids?

    Guys...I now truly believe what I just have described is the issue. Logically speaking, a variety of pads and different rotors including Hayes V6, tried by myself, and many others has not worked permanantly. The common factor in all this is Avid calipers. To much distance between the where the caliper sits onto the caliper bracket.
    I'm gonna go and check out the hardware of the other systems and compare a little to see what they've done. I bet there will be some differences in respect to distance between the caliper, caliper bracket, caliper hold down holes and washers...
    If I'm not climbing, I'm not riding.

  198. #198
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    XTR calipers are not slotted, and they come with shims to adjust the caliper in/out. Also, flat washers. No cupped washers. Not sure about other brands...

    BTW -- my new XTRs had a very similar warble, before I got them aligned. On my frame, the rear caliper mount needed one extra shim on one of the 2 holes to get the caliper aligned just right. Now, the XTR are perfect. So, I agree with the above, it does seem to be related to alignment. I just couldn't solve it with the J5 I had been using.

  199. #199
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    here's one sample of what I'm talking about.

    I bet these, don't howl. Note the solid looking caliper mount to caliper bracket. These look like they would not lean a whole lot if any. Also note the the number of washers and apparent bolt length.
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  200. #200
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    Quote Originally Posted by oscarc
    I bet these, don't howl. Note the solid looking caliper mount to caliper bracket. These look like they would not lean a whole lot if any. Also note the the number of washers and apparent bolt length.
    I think there is a misconception about the noises that are being heard. Mine don't howl, they warble. Intermittently as the pad goes across the spaces in the rotor.

    I'm sad to say that the spacing didn't work for me either. The front and rear are now both poop!

    Good news though!!!

    I'm getting mine warranty'd.

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