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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!
    Attached Images Attached Images

  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.

  7. #7
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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.

    I hate to advocate drugs, alcohol, violence, or insanity to anyone, but they've always worked for me.
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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
    Think Circles!
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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.

  48. #48
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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
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  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.
    Where am I? And how the hell did I get here?

  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.
    Where am I? And how the hell did I get here?

  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
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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...
    Where am I? And how the hell did I get here?

  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
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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.
    Where am I? And how the hell did I get here?

  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

  85. #85
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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.
    Where am I? And how the hell did I get here?

  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.
    Where am I? And how the hell did I get here?

  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...
    Ebay

    Or MTBR thread
    CDT

  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...
    Ebay

    Or MTBR thread
    CDT
    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
    MNTNBKR
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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.

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