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  1. #1
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    Caution;  Merge;  Workers Ahead! Help pls! Major front brake shudder in used 2013 Stumpjumper FSR. What would you do?

    Hi-

    I just purchased a used, 2013 Stumpjumper Comp FSR from a rental shop that is several hours away. When braking hard with the front brake, the vibrations are so bad the front fork/shock shudders. The shuddering is a massive back and forth flexing of the front shock. It is definitely being induced by vibrations in the brakes.

    I've read multiple forums and it seems it is likely caused by the stock Avids. The shop owner had installed new pads when I picked up the bike. We noticed a slight shudder, but after playing around with the pads and me doing several miles of downhill, it went away.

    I bought the bike and washed it at home. However, after washing the bike off, the shudder was back in full force.

    Is there anything I can tune/tweak to get rid of the shudder?

    I've read a lot of complaints on the Avids, even on new bikes. Are they really that bad? Should I try to replace them (was reading about Shimano IceTech)?

    Should I punt and try to return the bike? Returning the bike only makes financial sense if I can get a deal at my LBS, and the new bike would not have this issue.

    Thanks!

    PS Is this the best forum category to post this in?

  2. #2
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    Hi-

    For reference (and searching) I have the stock, Custom Avid Elixir 5 SL, hydraulic disc, HS-1 rotor. M: 180mm. I am not sure what type of replacement pads he used.

    The rears brakes seem fine, so far.

  3. #3
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    Help pls! Major front brake shudder in used 2013 Stumpjumper FSR. What would...

    Were the pads bedded in?

  4. #4
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    Quote Originally Posted by foxpuppet View Post
    Were the pads bedded in?
    Short answer: not formally.

    I asked the shop that. He said the pads are basically bedded when people ride downhill (this was up at Vail, so lift-ride up). That happened to be me, however, I did not do the jogging/walking thing I've read about because of the shop owner's advice. During the several miles of downhill I did play around with various amounts of pressure on the front brake. I didn't feel any shudder during my ride (very bumpy) or at the end of the day.

    The next day, after I rinsed the bike off the shudder was back BIG TIME. I only rode it up and down my street a few times to dry the bike off.

    Thanks for posting.

  5. #5
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    Avids are problems for many riders.
    Bolt this SLX on for $70 and you will not have problems.
    Clean the rotor with Brake Cleaner and I wipe my bike instead of hose it.
    BlueSkyCycling.com - Shimano SLX M666 IceTech Disc Brake w/Adapter

  6. #6
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    Quote Originally Posted by eb1888 View Post
    Avids are problems for many riders.
    Bolt this SLX on for $70 and you will not have problems.
    Clean the rotor with Brake Cleaner and I wipe my bike instead of hose it.
    BlueSkyCycling.com - Shimano SLX M666 IceTech Disc Brake w/Adapter
    Keep in mind the rear brake cable needs to be 1700 mm version. The stock 1200 from blue sky is not long enough. This is a special cable and not the typical brake cable that cost 19.99. Is more like 47 to 54 bucks . Add labor to it and these slx brakes from blue sky are not cheap.

    Get the xt from them that has the 1700mm cable stock.
    Last edited by Loll; 09-03-2013 at 08:24 AM.

  7. #7
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    Shuddering is caused by different braking force over the surface of the rotor. Could be unevenly bedded in, contaminated, warped or worn out of whack. It's not an Avid specific problem; I'm riding a '13 Epic with a front Magura brake with similar problems.

    Get the bike shop to put on a new rotor and pads and make sure the pistons are moving evenly. Follow the Avid bedding in procedure. Let them keep the old parts.

    FWIW, the Avids on my '11 have worked perfectly through several pad changes, although they were haywire when I got the bike used. And the Maguras have the dreaded turkey gobble when warm, so it isn't an Avid patent noise after all. You only hear from the people having problems and there are zillions of Avids out there. That said, Shimanos are a quieter and less problematic brake system overall.

  8. #8
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    Avids are notorious for these sorts of problems. I fought with the Elixir 4's on my 2010 FSR XC for almost two years before giving up and getting some SLX brakes. I kept the original rotors. No problems since the switch. Here is a 37 page thread on Avid vibrations and noise.

    The Juicy brake turkey warble/vibration MEGA THREAD

    Even though it is titled "juicy brake turkey warble...." there are probably 2 or 3 hundred posts from people with Elixirs. There are several "solutions" in this thread. I tried a few, nothing really took care of the problems I was having.

  9. #9
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    Quote Originally Posted by philipb View Post
    Avids are notorious for these sorts of problems. I fought with the Elixir 4's on my 2010 FSR XC for almost two years before giving up and getting some SLX brakes. I kept the original rotors. No problems since the switch. Here is a 37 page thread on Avid vibrations and noise.

    The Juicy brake turkey warble/vibration MEGA THREAD

    Even though it is titled "juicy brake turkey warble...." there are probably 2 or 3 hundred posts from people with Elixirs. There are several "solutions" in this thread. I tried a few, nothing really took care of the problems I was having.
    Thanks. I read through that thread but didn't see much on shudder. The net of that thread was that Avid's seem to be higher maintenance and problematic, however, most threads of that nature focus on issues. I didn't read a clear fix.

  10. #10
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    Quote Originally Posted by Loll View Post
    I

    Keep in mind the rear brake cable needs to be 1700 mm version. The stock 1200 from blue sky is not long enough. This is a special cable and not the typical brake cable that cost 19.99. Is more like 47 to 54 bucks . Add labor to it and these slx brakes from blue sky are not cheap.

    Get the xt from them that has the 1700mm cable stock.
    Are you saying that buying locally includes install, or that you need to add more parts-cost than what is being shown?

    Thanks,

  11. #11
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    Thanks for all of the responses.
    I'll call the bike shop and see what they can offer. The shop is 2 hours away, so it's not easy to get there.

    They did put on new pads and tweak around with them while I was there. They also centered and re-centered the calipers. How much of this might be related to bleeding?

    The shop also carries Shimano. He offered parts at his cost. Maybe I can swing the swap-out.

    I paid $1800 out the door ($1650 plus tax). If I have to rebuild a lot, I'm getting close in price to a new, stock bike. How much would you deal with versus just trying to return the bike? I've read that a lot of people buy a new bike and immediately upgrade parts. I can see why, but my goal is to stay within a price. I'd hate to get a new bike and have a similar issue.

    Any general thoughts on the dollars and what you end up with?

  12. #12
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    The Avids are hit and miss for sure, had different trouble with both my juicy 3 and 5 brakes. I still have trouble with the 3's but the 5's quit giving trouble after short period. Been riding them now for 4 yrs off and on. Quiet great braking power. Still having trouble with shudder with 3's on a 09 fsr XC Speci. Best brakes I've had so far are X2 hopes. But I've ridden Shimano XT and SLX both seem good, quiet and smooth
    Disclaimer: Always get a second opinion cause I'm just guessing

  13. #13
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    The xt come stock with 1700 mm cable if u buy from bluesky. It is more expensive up front. The Slx , u need to buy the expensive longer cable and have it install if u dont know how to do it well yourself. With labor, the xt is cheaper.

    Buying locally, u can ask the shop to get the 1700 version, but it is likely much more expensive than bluesky.

    The elixir on my bike suck. I did change brake pad and rotor per the stam brake thread. It works bit other problems arised. Decide to toss them. Funny i had juicy on my nomad and it works great. Not one problem after switching to organic pad. I am thinking sram and specialized dont go well together

  14. #14
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    Quote Originally Posted by bulerias View Post
    Shuddering is caused by different braking force over the surface of the rotor. Could be unevenly bedded in, contaminated, warped or worn out of whack. It's not an Avid specific problem; I'm riding a '13 Epic with a front Magura brake with similar problems.

    Get the bike shop to put on a new rotor and pads and make sure the pistons are moving evenly. Follow the Avid bedding in procedure. Let them keep the old parts.

    FWIW, the Avids on my '11 have worked perfectly through several pad changes, although they were haywire when I got the bike used. And the Maguras have the dreaded turkey gobble when warm, so it isn't an Avid patent noise after all. You only hear from the people having problems and there are zillions of Avids out there. That said, Shimanos are a quieter and less problematic brake system overall.
    Err, no, it's caused by the caliper resonant frequency. This happens with cars and all sorts of other vehicles, although if designed properly, it usually doesn't happen. It's an oversight and unpredicted result usually of joining two components/systems and not understanding the interaction between the two. Tacoma Narrows bridge. That's your Avid shudder.

    One way this is sometimes solved is by adding stick-on weights to the caliper. Otherwise it can be a total wild goose chase trying to come up with a solution, other than switching brakes.
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  15. #15
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    Hmmm.... They guy I bought the bike from mentioned he "upgraded" the brakes. I know he at least upgraded the levers because I saw the broken one he was fixing up.

    So... at least the levers and possible the rest of the set-up are Avid Elixir Trail 9s. Are these supposed to be an upgrade from the stock parts on the bike? Can you tell from the attached pics if he also upgraded the calipers?

    The hydraulic cabling/tubing is attached with several zip ties. Did he use the wrong length cable when he put these on (I can take a pic if needed)? Would that cause any issues? Do you see any issues with the way the calipers are mounted?

    Thanks!


    Help pls!  Major front brake shudder in used 2013 Stumpjumper FSR. What would you do?-img_1707.jpgHelp pls!  Major front brake shudder in used 2013 Stumpjumper FSR. What would you do?-img_1704.jpgHelp pls!  Major front brake shudder in used 2013 Stumpjumper FSR. What would you do?-img_1702.jpg

  16. #16
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    Looks (by the wear marks) to be mounted too close to the hub.

  17. #17
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    Avid brakes suck. You have a nice bike, just throw on a new brakeset if money allows.
    Get some 80 grit (or whatever you have) sandpaper and sand the pads down until they look "new". Wipe the rotors off with alcohol. Worked for my Maguras.
    Livin' the dream.

  18. #18
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    Quote Originally Posted by broncbuster View Post
    Looks (by the wear marks) to be mounted too close to the hub.
    I am wondering if those are scuff marks caused by shudder.

    Do the mounting brackets (?) with the 17.5mm marking look correct/appropriate? I wonder if they are not stiff enough.

    Any thoughts on that?

  19. #19
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    Can you tell if the pads are riding in the appropriate area of the disc? If so something else has to be making those marks and probably the cause of the shudder. The hardware looks normal and should be stiff enough. If the pads are the cause of the marks then maybe a 170mm disc or different hardware is the answer?

    I had a bike (with Hayes Nine brakes) that was always giving me a lot of problems I finally converted it to mechanical disc brakes. Not a bad way to go, the ones I got are very easy to adjust and very strong.

  20. #20
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    Alligator Windcutter Colored Disc Rotor | Alligator | Brand | www.PricePoint.com
    These will solve your problem Ive put them on a dozen bikes with the issues you are having and it cured it on everyone of them... avid rotors suck...
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  21. #21
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    You can try going back to the 160MM rear rotor instead of the 180mm with that hookie spacer set up.
    Personally I hated the Avid breaks on my SJ, I'd just say get the SLX or XT brakes and be done with the problem.
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  22. #22
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    Quote Originally Posted by Jayem View Post
    Err, no, it's caused by the caliper resonant frequency. This happens with cars and all sorts of other vehicles, although if designed properly, it usually doesn't happen. It's an oversight and unpredicted result usually of joining two components/systems and not understanding the interaction between the two. Tacoma Narrows bridge. That's your Avid shudder.

    One way this is sometimes solved is by adding stick-on weights to the caliper. Otherwise it can be a total wild goose chase trying to come up with a solution, other than switching brakes.
    I think the shudder the OP was referring to was a pulsing that tends to make the fork move fore and aft a bit. In a sense, the fork is resonating to a pulse in the brake system.

    The calliper resonant frequency is in a completely different frequency range altogether. If the shudder is at wheel rotation speed then you've got what I'm talking about, i.e. once per revolution or twice. Callipers will squeal or honk. Rear brakes attached to stays can resonate with the stay but front brakes attach to fork legs and they are oil damped and considerably larger.

    If the rotor is kooky or unevenly bedded it isn't a resonance in that sense and no amount of voodoo will fix it.

  23. #23
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    Quote Originally Posted by TwoTone View Post
    You can try going back to the 160MM rear rotor instead of the 180mm with that hookie spacer set up.
    Personally I hated the Avid breaks on my SJ, I'd just say get the SLX or XT brakes and be done with the problem.
    Hi. For clarity, the pics are of the front brakes/rotors.

    The rear brakes are thankfully pretty good.

  24. #24
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    Quote Originally Posted by broncbuster View Post
    Can you tell if the pads are riding in the appropriate area of the disc? If so something else has to be making those marks and probably the cause of the shudder. The hardware looks normal and should be stiff enough. If the pads are the cause of the marks then maybe a 170mm disc or different hardware is the answer?
    I played around a little this weekend and noticed when I squeeze the front brakes, the rotor bends a little. The rotor is not warped, and the "bending" is there, regardless of the wheel position. I'm assuming this means the caliper has somehow rotated.

    When I picked up the bike, the tech showed me his "trick" of loosening both screws on the front caliper, squeezing the brakes to center it, and then tightening in place. Assuming his trick had properly aligned the brakes, how did they move so much, and why would they essentially rotate? Is it common for brakes to rotate like that?

    Anything I should know before I try the same trick? Do I just hand-tighten the calipers in place?

  25. #25
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    I've run into this problem with headsets without enough preload and forks with trashed sliding bushings. So check that before you spend money.
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  26. #26
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    Quote Originally Posted by Tweakophyte View Post
    Hi. For clarity, the pics are of the front brakes/rotors.

    The rear brakes are thankfully pretty good.
    Again get a proper adaptor or back to a 160mm rotor. I think just adding a large spacer is a half assed way to do it.

    Here is an example, but this takes it from 160mm to 203mm rotor, but it should give the point:
    Avid CPS Disc Brake Adapter Post Mount 203mm Rotor from BikeBling.com
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    While I won't claim to know all of the available adapters out there, the ones on your fork look hokie and rigged. I can't help but think that setup would allow for more flexing in the two brake mounting bosses thus allowing the caliper to oscillate.
    I'm with TwoTone, get the proper spacer then go from there.

  28. #28
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    Quote Originally Posted by TwoTone View Post
    Again get a proper adaptor or back to a 160mm rotor. I think just adding a large spacer is a half assed way to do it.

    Here is an example, but this takes it from 160mm to 203mm rotor, but it should give the point:
    Avid CPS Disc Brake Adapter Post Mount 203mm Rotor from BikeBling.com
    Probably your best bet. But in the mean time you can find some YouTube videos I'm sure that would help you with the adjustment. The trick your LBS showed you is about all I got and I didn't have all that much luck doing it that way regardless. Any small warp in the rotor and they will rub and then after a ride it seems to be out of position again at least that was the case for me. There are better ones with better adjustment features and the manual one I got were super easy to adjust.

  29. #29
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    Quote Originally Posted by KThaxton View Post
    While I won't claim to know all of the available adapters out there, the ones on your fork look hokie and rigged. I can't help but think that setup would allow for more flexing in the two brake mounting bosses thus allowing the caliper to oscillate.
    I'm with TwoTone, get the proper spacer then go from there.
    I agree with this too. Those long spacers are definitely a likely source of the vibration.
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  30. #30
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    You could try putting a torque wrench to the mounting screws. Those spacers do look kludgy, but as long as they're adequately loaded, it might not be that bad... Still, a regular, purpose-built adapter has got to be better.
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    I had a real bad shudder on my cyclocross bike(rim brakes),turned out to be a worn out headset bearing. It felt smooth and tight but touch the brakes and I thought the fork was going to snap.

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    Quote Originally Posted by TwoTone View Post
    Again get a proper adaptor or back to a 160mm rotor. I think just adding a large spacer is a half assed way to do it.

    Here is an example, but this takes it from 160mm to 203mm rotor, but it should give the point:
    Avid CPS Disc Brake Adapter Post Mount 203mm Rotor from BikeBling.com
    Okay... I'm listening. Please clarify... the 1800mm front rotor is stock on these stumpies, right? If so, what adapter should go with these Avid 9 Trails? Did my guy re-use what came on the bike or did he hack something?

    One more... is 1600mm what the standard, shock-mounting spot is for, then you typically get an adapter? I'm just wondering if the bike came with 1800mm why it wouldn't be more seamless.

    Thanks again!

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    Help pls!  Major front brake shudder in used 2013 Stumpjumper FSR. What would you do?-photo-4-.jpgThose are legitimate adaptors made by Avid, but most bikes come with this style. I don't think they are the problem.

  34. #34
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    Quote Originally Posted by Tweakophyte View Post
    Okay... I'm listening. Please clarify... the 1800mm front rotor is stock on these stumpies, right? If so, what adapter should go with these Avid 9 Trails? Did my guy re-use what came on the bike or did he hack something?

    One more... is 1600mm what the standard, shock-mounting spot is for, then you typically get an adapter? I'm just wondering if the bike came with 1800mm why it wouldn't be more seamless.

    Thanks again!
    What size is your frame? My 2012 came with a 200mm rotor. Also, go on the Specialized website, go to support and archive then look up your bike. You can click on the picture and zoom in, they don't come stock with that hookie shit.


    It's $10, try it first before wasting anymore time.

    It's hard to see in the picture, but look at the correct part, if you look closely at the 2 mounting surfaces one is at a 90degree angle the other isn't. The two spacers you have aren't going to reproduce that and that could be enough to cause what you have.

    It may not fix it, but you have to start with what you know is wrong and those 2 spacers are wrong.

    Help pls!  Major front brake shudder in used 2013 Stumpjumper FSR. What would you do?-avid_acc_cpsmntbracket_postmnt_20mm_lrg.jpg
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    Hi-

    The frame is medium, so 180s (vs 200s) are stock. L/XL gets 200s.

    FWIW, this looks to be the kit he used.

    I called the shop owner yesterday, and he said that was the stock mounting part. Regardless, I agree I should get a better part as my next step.

    Are you 100% sure that is the part (shape) I need for the fox shocks and the elixir 9 trails? I ask because unlike stuff I've (tried to) read for shimano, I can't seem to find a chart that says "if this then use that".

    Thanks again to everyone!

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    PS Assuming I get the bracket, do I also need to get a hardware kit? Does it come with what I need? Do I have the parts already?

    Does anyone happen to have a pic of their current config?

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    Good advice you're getting but if all else fails this will fix your problem.

    Avid BB7 Front Rear Caliper 160mm G3 Rotors Speed Dial 7 SD7 Levers | eBay

  38. #38
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    Quote Originally Posted by Tweakophyte View Post
    Hi-

    The frame is medium, so 180s (vs 200s) are stock. L/XL gets 200s.

    FWIW, this looks to be the kit he used.



    I called the shop owner yesterday, and he said that was the stock mounting part. Regardless, I agree I should get a better part as my next step.

    Are you 100% sure that is the part (shape) I need for the fox shocks and the elixir 9 trails? I ask because unlike stuff I've (tried to) read for shimano, I can't seem to find a chart that says "if this then use that".

    Thanks again to everyone!
    Pretty sure, most post mounts are for 160mm, so you see the 20mm on the bracket? That gets you to 180MM, the 200mm bracket has 40mm on it.

    You have to find out from the retailer if it comes with the bolts.

    I'll have to look at a medium bike next time I'm at my LBS.
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    Quote Originally Posted by TwoTone View Post
    Pretty sure, most post mounts are for 160mm, so you see the 20mm on the bracket? That gets you to 180MM, the 200mm bracket has 40mm on it.

    You have to find out from the retailer if it comes with the bolts.

    I'll have to look at a medium bike next time I'm at my LBS.
    Thanks. Hmmm... 160 plus 20 = 180... then why do mine say 17.5mm?

    I ordered the 20mm part above. Fingers crossed.

  40. #40
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    The change in radius is only 10 mm. However, the brake caliper isn't being moved radially, exactly. And we don't know if 17.5 mm is the length or something else. If you're curious, measure them when you take them off and let us know what it was.
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    Quote Originally Posted by Tweakophyte View Post
    I played around a little this weekend and noticed when I squeeze the front brakes, the rotor bends a little. The rotor is not warped, and the "bending" is there, regardless of the wheel position. I'm assuming this means the caliper has somehow rotated.

    When I picked up the bike, the tech showed me his "trick" of loosening both screws on the front caliper, squeezing the brakes to center it, and then tightening in place. Assuming his trick had properly aligned the brakes, how did they move so much, and why would they essentially rotate? Is it common for brakes to rotate like that?

    Anything I should know before I try the same trick? Do I just hand-tighten the calipers in place?
    That trick only gets you close Tweak. You still have to make small adjustments to get the caliper centered over the rotor and also square to the rotor surface. You'll be able to see the space between the pads and the rotor while you are doing this. Also, small spins of the wheel while you are going through centering process while 'lightly' dragging the pads (squeezing the lever) will tell you by sound if the pads aren't hitting the rotor optimally ( even if it looks good to the eye)

    The reason the rotor is flexing to the side like that is 'the trick' that the tech used generally isn't a sure bet, and rather than checking to see the result of his trick, he just relied on the belief that it worked. It didn't. The caliper isn't centered and it's been that way since he did that. Nothing you did. It's even more of a sloppy technique with Avid's due to their CPU ( I think they're called) washers. They will shift everytime if you just torque on the bolts. Personally with Avid's, I will sight position the caliper in relation to the rotor, giving small spins of the wheel during the process. It is important to make small, alternating tightening turns to the bolts so that you don't cause the caliper to shift out of your intended position.

    Just take your time, you'll get it figured out, and you'll get them dialed.

  42. #42
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    Organic pads. Alligator Serration rotors. Glue the pads to the spring with CRC Brake Quiet. Done.
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  43. #43
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    Update....
    I got the avid 20mm post-to-post adapter, but did not mount it. It's smaller than the current adapter, which I have confirmed is stock on the small/medium stumpy with 180mm rotors (see below).

    Help pls!  Major front brake shudder in used 2013 Stumpjumper FSR. What would you do?-img_1722.jpg

    For clarity, large/extra-large come with 200mm rotors, and a completely different adapter. (checked both out at an lbs)

    I messed with the brakes a few times, trying to do a quick alignment of them... no love yet. Right now they seem to angle in (not toe-in) so the bottom of the left caliper is hitting first.

    Is this just an exercise in patience? Is something damaged (i.e. can the fork-mounts get our of alignment)? I'm thinking it's the former, and that the CPS "washers" allow for too much play. Anyone work with these, specifically? I wonder if there is an angle to them or something I am missing. Strange that this would be that tough.

    Are the shimanos that tricky to set up? If my current set-up doesn't use a "standard" 20mm p-to-p mount, would the shimanos work?

  44. #44
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    Quote Originally Posted by jochribs View Post
    That trick only gets you close Tweak. You still have to make small adjustments to get the caliper centered over the rotor and also square to the rotor surface. You'll be able to see the space between the pads and the rotor while you are doing this. Also, small spins of the wheel while you are going through centering process while 'lightly' dragging the pads (squeezing the lever) will tell you by sound if the pads aren't hitting the rotor optimally ( even if it looks good to the eye)

    The reason the rotor is flexing to the side like that is 'the trick' that the tech used generally isn't a sure bet, and rather than checking to see the result of his trick, he just relied on the belief that it worked. It didn't. The caliper isn't centered and it's been that way since he did that. Nothing you did. It's even more of a sloppy technique with Avid's due to their CPU ( I think they're called) washers. They will shift everytime if you just torque on the bolts. Personally with Avid's, I will sight position the caliper in relation to the rotor, giving small spins of the wheel during the process. It is important to make small, alternating tightening turns to the bolts so that you don't cause the caliper to shift out of your intended position.

    Just take your time, you'll get it figured out, and you'll get them dialed.
    Thanks... read this before trying to tweak these in place. Any comment on the washers? Do you have this set-up?

  45. #45
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    I would be very surprised if your post mount is not standard.

    Do you have Avid rotors?

    For brake centering, in the past I've found it helpful to remove the zip tie on the hose guide closest to the brake caliper. The hose can put enough lateral load on the caliper to make it hard to get the alignment right.

    Are you keeping the brake applied when you tighten the bolts? I actually tie my handle down to do this. Since I only have two hands, I find it very helpful.
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  46. #46
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    Quote Originally Posted by Tweakophyte View Post
    Update....
    I got the avid 20mm post-to-post adapter, but did not mount it. It's smaller than the current adapter, which I have confirmed is stock on the small/medium stumpy with 180mm rotors (see below).

    Click image for larger version. 

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    For clarity, large/extra-large come with 200mm rotors, and a completely different adapter. (checked both out at an lbs)

    I messed with the brakes a few times, trying to do a quick alignment of them... no love yet. Right now they seem to angle in (not toe-in) so the bottom of the left caliper is hitting first.

    Is this just an exercise in patience? Is something damaged (i.e. can the fork-mounts get our of alignment)? I'm thinking it's the former, and that the CPS "washers" allow for too much play. Anyone work with these, specifically? I wonder if there is an angle to them or something I am missing. Strange that this would be that tough.

    Are the shimanos that tricky to set up? If my current set-up doesn't use a "standard" 20mm p-to-p mount, would the shimanos work?
    Put a zip tie around your fork and cut I so it's just off the rotor and spin the wheel, is it warped? IF not it's just patience trying to get them right. When you tighten the bolts it wants to move the caliper. Personaly have never had the hold the brakes tighten the bolts work for me.

    I snug down the bolts until the caliper is hard to move by hand, then I just make tiny adjustments until it doesn't rub.
    Then I do my best to slowly tighten the bolt while holding the caliper from moving. Trail and error.
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  47. #47
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    Quote Originally Posted by Tweakophyte View Post
    Thanks... read this before trying to tweak these in place. Any comment on the washers? Do you have this set-up?
    I personally am a Shimano guy. I have XTR's and love them, BUT my wife's bike has X7's and I am her mechanic. The CPS washers ( I stupidly called them CPU before...that's a computer thing isn't it?) are generally a pain, but they are definitely dial-able.

    What I said in the post you responded to and what TwoTone has said also, is to fore-go the trick that the tech used. It just does not work, especially with brakes that have those washers. They just shift too much, and the torque developed by tightening the bolts is enough to exchange fluid from side to side of the caliper and cause what you would think is centered over the rotor to...viola!...not be once you let go of the lever after tightening the bolts.

    With your Avids, you have a pretty good line of sight looking from the topside of the caliper (or rear, since it is the one on your fork we are dealing with) and see the pads, and the rotor in between. You are aiming to have an even amount of space on both sides of the rotor in relation to the pads. This facilitates the pads hitting the rotor evenly, and at the same time. You get even wear on the pads/rotor, and nice and firm feeling levers too. The other thing that is important to look for and listen for is if the pads/caliper are square to the rotor in the vertical sense as well. Because of those washers, the caliper can 'tilt' in relation to the rotor surface as well. This is why eyeballing clearances, and also doing light spins and listening, and tightening in SMALL incremental amounts, alternating from bolt to bolt is the way to go with your brakes. Really, it is the proper technique for any brake out there, but imperative for Avids.

    I'm wondering if you need to a good caliper cleaning, and a rebleed? I know you had said that the rotor was flexing when you'd pull the lever, which would indicate improper caliper alignment, but did you note whether or not the pads were moving evenly and recessing evenly? It could be that the pistons have a bias to one side. One thing you can do for a start when you go to set up your PM adapter, is pull your pads and throw in the bleed block. It should have come with the bike, although since it was used, they probably didn't give you that stuff. If you don't have one, grab an Avid Bleed kit at a local shop. Once you take out the pads, carefully press the pistons back with a tire lever, throw the bleed block in, and give the lever a few pumps to reset your pistons. Then, throw the pads back in and go through the caliper set up process.

    I personally clean out the caliper and even the pads themselves with cotton swabs that I dip in Denatured Alcohol. I use a small cup, like a Stans scoop, and a good bunch of swabs, never using the swab to dip in the fresh alcohol twice. Use a fresh end, and keep cleaning until the swabs aren't looking like charcoal. (Like in Seinfeld, no double dipping) Regular Iso alcohol works too, but make sure that you get the 90% stuff. The other ones leave residue, which is why I prefer using Denatured, nothing left behind to contaminate whatsoever, and evaporates like you wouldn't believe.

    Avids are good brakes, they just need to be bleed well and adjusted properly. You'll get this Tweak, and be a lot more knowledgeable in the end.

  48. #48
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    Tweak, looking at your pics, it seems that your rotor might have been worn in by having the caliper in the wrong position previously. Like, the caliper was in position for a 200mm rotor and a wheel with a 180mm was run. Can you feel a slight difference with your fingers or finger nail between those differently colored wear areas on the rotor?

    Being that this was a used rental bike, (that was said previously, right?) it is a strong possibility that some mismatching of parts was done at some point during the bikes use. It might be a good idea to replace the rotor AND the pads and go from there if this was the case. I wouldn't bother sanding or any of that sort of nonsense. Something doesn't look right in those pics as far as the rotor is concerned. It shouldn't look like there are two separate pad tracks on the rotor.

  49. #49
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    Admittedly I have not read all the responses, but can tell you that I experienced front wheel 'shuddering' on my 2011 stumpy fsr elite on only one occasion that proved to be due to loosening of one of the two bolts of the brake caliper. Check the tension of those bolts at the start of a ride and best to do so after a rough rock garden/gravity descent too just to be safe to then know they're holding tension properly.

  50. #50
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    Quote Originally Posted by Tweakophyte View Post
    Update....
    I got the avid 20mm post-to-post adapter, but did not mount it. It's smaller than the current adapter, which I have confirmed is stock on the small/medium stumpy with 180mm rotors (see below).

    Click image for larger version. 

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    For clarity, large/extra-large come with 200mm rotors, and a completely different adapter. (checked both out at an lbs)

    I messed with the brakes a few times, trying to do a quick alignment of them... no love yet. Right now they seem to angle in (not toe-in) so the bottom of the left caliper is hitting first.

    Is this just an exercise in patience? Is something damaged (i.e. can the fork-mounts get our of alignment)? I'm thinking it's the former, and that the CPS "washers" allow for too much play. Anyone work with these, specifically? I wonder if there is an angle to them or something I am missing. Strange that this would be that tough.

    Are the shimanos that tricky to set up? If my current set-up doesn't use a "standard" 20mm p-to-p mount, would the shimanos work?
    Tweak, I don't think you should be using the CPS washers at all with the XO trail calipers. Pretty sure avid stopped using them with these (and other high end) brakes. Case in point, look at the wear marks on your rotors - the caliper is sitting too high, because of the spacers and CPS washers. I think you purchased the correct post bracket (that's the 20mm right?) Try just the bracket and the caliper (maybe a small flat washer or two to custom fit)

    I had to go through this recently when I retrofitted XO trail brakes and a Fox 34 on my stumpy, replacing the Elixer 5's (CPS and standoffs like your pic) and Revelation fork. I used the 20mm post bracket and it fit great. I'll try to get some pics later to show better.


    There's a pic down on this page showing the fork, 20mm post bracket, and no CPS washers: Tested: Avid XO Trail Brakes « Mountain Flyer Magazine


    Here's a little more info on the XO trail brake during release. The comments talk a bit about no CPS washers. Admittedly some pics show CPS washers but they are above the calipers and pretty useless in function and fit in this position, I think that's an oversight by the article's author: New Four Piston Avid X0 Trail Brakes Unveiled ? Specs, Weights & First Rides!

  51. #51
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    Quote Originally Posted by bad andy View Post
    Tweak, I don't think you should be using the CPS washers at all with the XO trail calipers. Pretty sure avid stopped using them with these (and other high end) brakes. Case in point, look at the wear marks on your rotors - the caliper is sitting too high, because of the spacers and CPS washers. I think you purchased the correct post bracket (that's the 20mm right?) Try just the bracket and the caliper (maybe a small flat washer or two to custom fit)

    I had to go through this recently when I retrofitted XO trail brakes and a Fox 34 on my stumpy, replacing the Elixer 5's (CPS and standoffs like your pic) and Revelation fork. I used the 20mm post bracket and it fit great. I'll try to get some pics later to show better.


    There's a pic down on this page showing the fork, 20mm post bracket, and no CPS washers: Tested: Avid XO Trail Brakes « Mountain Flyer Magazine


    Here's a little more info on the XO trail brake during release. The comments talk a bit about no CPS washers. Admittedly some pics show CPS washers but they are above the calipers and pretty useless in function and fit in this position, I think that's an oversight by the article's author: New Four Piston Avid X0 Trail Brakes Unveiled ? Specs, Weights & First Rides!
    Nice catch Andy. That would explain things completely. Good thing they are getting away from those washers.

    Tweak, if you look at the wear area on your rotors, and the difference in height of the adapter vs. the spacers/washers, it is exactly what you need to correct it. Andy looks to be right on the money. I would still replace the pads and rotor.

  52. #52
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    added pic...

    Quote Originally Posted by jochribs View Post
    Nice catch Andy. That would explain things completely. Good thing they are getting away from those washers.

    Tweak, if you look at the wear area on your rotors, and the difference in height of the adapter vs. the spacers/washers, it is exactly what you need to correct it. Andy looks to be right on the money. I would still replace the pads and rotor.
    I nabbed a pic of my front setup:

    Help pls!  Major front brake shudder in used 2013 Stumpjumper FSR. What would you do?-xotrailcaliper.jpg

    Also, I would replace the pads - definitely - they are probably worn all kinds of funny. And to address the initial issue, your shudder - if the correction to the mounting doesn't fix it - replace the rotor as well. I had shudder in my rear 160mm and I replaced the rotor all is good now. 8)

  53. #53
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    I think he should definitely replace the rotor at the same time. There are definitely two different wear paths on it, in different color... possibly two separate pad materials bed in. I'd bet that the rotor has different wear depth in the two spots as well, which if so, is going to pooch the next pads too.

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    Whew.... lots of great updates here. Thanks!

    - Does it matter that I have Trail 9s vs the XOs? (I think not)
    - The CPS washer set up *is* standard on the medium stumpys (double checked at the shop). Is the exlir 5 and the elixir 9 trails mounting that different.

    I took a stab at superimposing the images. It's not clear, but you can see the 5s bulging below the 9s. What part of the brake is that? Does this mean the 9s are too high up on the rotor?

    Help pls!  Major front brake shudder in used 2013 Stumpjumper FSR. What would you do?-collages.jpg

    Andy... any chance you get a pic of your setup a little more square to the rotor so I can try to mush your setup with mine?

  55. #55
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    Quote Originally Posted by jochribs View Post
    I think he should definitely replace the rotor at the same time. There are definitely two different wear paths on it, in different color... possibly two separate pad materials bed in. I'd bet that the rotor has different wear depth in the two spots as well, which if so, is going to pooch the next pads too.
    I'll keep this on the list. I've noticed a lot of rotors have two different wear patters, even in the links to the XOs. I'm thinking the rotors are mounted too high on the rotor... so first fix when (if) I get some time this weekend.

    Thanks again to everyone!

  56. #56
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    Quote Originally Posted by Tweakophyte View Post
    Whew.... lots of great updates here. Thanks!

    - Does it matter that I have Trail 9s vs the XOs? (I think not)
    - The CPS washer set up *is* standard on the medium stumpys (double checked at the shop). Is the exlir 5 and the elixir 9 trails mounting that different.

    I took a stab at superimposing the images. It's not clear, but you can see the 5s bulging below the 9s. What part of the brake is that? Does this mean the 9s are too high up on the rotor?

    Click image for larger version. 

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    Andy... any chance you get a pic of your setup a little more square to the rotor so I can try to mush your setup with mine?
    I'll try at some point to take a pic more squarely.
    I am not sure, but I think the trail series definitely do not use CPS washers, though the rest of elixir series still do. (just looked at pics on sram/avid site) My elixir 5's certainly did come with CPS washers and standoffs.

    The fact that there are different wear patterns, whether it be on a "pro-built" bike from a LBS, or some article on the internet doesn't matter. It's still wrong, and not optimal. The calipers are too high. Really, it's about making sure as much of the brake pad lines up evenly and makes contact with the rotor surface as possible. That would ensure the most efficient braking. You can visually assess this, and utilize various resources to ensure the best fit, whether it be a mounting bracket, cps washers, flat washers, standoffs, or any combo of the aforementioned. That being said, though things can be hob-jobbed to work, there is a recommended way to mount things - such as the post mount bracket and no CPS washers

  57. #57
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    ^+

    The reason that the rotor is waved is so that when the calipers (and thus the pads) are in proper position, it (the rotor) sweeps all parts of the pads. This ensures even wear on the pads and not a 'step' wearing into the pads that in eventuality could cause the pads to contact each other and reduce the force on the rotor.

    Believe us, you should not be seeing two separate wear areas. And the wear area 'needs' to be in the zone that is indicative of the pads getting full sweep at their uppermost point when the high points of the rotor come past them. A teeny sliver of unbraked upon rotor in these high spots (on the HS1's) is optimal.

    This is why I am saying it is pennywise and pound foolish to try and preserve either of those two components of the brake system. Just replace the rotor and the pads and adjust fresh. I'll bet dollars to donuts that your issues will vanish.

    Also, I really don't see the value in trying to superimpose two totally different pictures to see where things should be. There is a correct position (like I described above) and there is a wrong position. It may vary from company to company, rotor style to rotor style, but the fundamentals of proper set up aren't exclusive to any one brake. I recommend you do like Andy has advised, and remove the washers from underneath. The reason they are still on the top side in Andy's supplied pics would make sense that they are helping the bolts to not bottom out and nothing more. Fiddle with position, and find the proper set-up. Alternately, call Avid (SRAM) on Monday and ask them. Info straight from the horses mouth is always a good thing.

  58. #58
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    Quote Originally Posted by jochribs View Post
    ^+
    ...Believe us, you should not be seeing two separate wear areas. ...
    I believe. This has all been VERY helpful.

    So, check out my progression from yesterday:

    I already posted the difference in mounting depth/standoff. Here is the hardware that came in the package versus what was on the bike (stainless). Note, the shorter bolt is for the bottom part of the fork.
    Help pls!  Major front brake shudder in used 2013 Stumpjumper FSR. What would you do?-img_1736.jpg

    Here is a shot of the pad wear. Kudos to everyone that caught the wrong standoff size.
    Help pls!  Major front brake shudder in used 2013 Stumpjumper FSR. What would you do?-img_1739.jpg

    I tried to mount the caliper using no CPS/washers, but it clearly would not work. The bolts are in as far as I felt comfortable cranking on them. This was interesting since the lower bolt is shorter than the bolt that came in the package (note how deep it would need to go).
    Help pls!  Major front brake shudder in used 2013 Stumpjumper FSR. What would you do?-img_1742.jpg

    Here is the caliper attached with some CPS washers.
    Help pls!  Major front brake shudder in used 2013 Stumpjumper FSR. What would you do?-img_1750.jpg

  59. #59
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    I rode the bike on my streets to check out the caliper alignment and am convinced I can get these to work. It was much easier to get these in place without any of the rotor flexing and strange angles, now that I have the correct post-to-post bracket. I also felt the rotor in several spots and did not notice and groove.

    I did a bedding process for the new brake-pad area a few times, then experimented with front brake. I'll report that I still get shudder, but clearly the pads are not worn evenly.

    The pads were new when I picked up the bike, and they were used on about 10-15 miles of cross-country/downhill down Vail (twice down Radio Flyer to Big Mamba).

    Now my questions:
    - Is there any chance to save the pads, or is it not worth the trouble? If I try to wear in the "new" part of the pads, will I ruin the rotors?
    - Are the pads just held in by that pin? I tried to take them off and could not get the pin to slide easily and did not want to force it. (yes, took off the retention piece.) Any other toold to swap pads?
    - What pads should I use? Just the XO trails or is there another pad I should try?
    - Do I really need new rotors or can I try just the pads?
    - Do I need shorter bolts? If so, what is the next standard size down? I was surprised I still had to use the CPS washers to mount the calipers. *** Edit: The CPS Washers are part of the setup. Found this on Avid website. ***

    Anything else I should know?
    Thanks!
    Last edited by Tweakophyte; 09-22-2013 at 07:20 AM. Reason: answered one question

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    Help pls! Major front brake shudder in used 2013 Stumpjumper FSR. What would...

    Excellent! It looks like you're spot on to proper caliper height. I'll just summarize a few points as I'm watching my 10-mo. old right now

    1) I second jochribs' opinion to replace both pads and rotor. This will give you a clean slate and ensure every thing is freshy fresh and as it should be. Hence, no worries about existing conditions; uneven pads, rotor, warping etc.
    2) you can obviously buy avid pads, though there are other options. (Kool stop, ebc, etc.) I've had good experience with truckerco and they are very kind to the wallet.
    3) I played around with bolt length, I didn't want a stack of washers to achieve proper fit. Admittedly I was blinging a bit so found some black titanium bolts on eBay, at the approximate size. I did have to take a Dremel to one of them to make it a bit shorter. Sorry I forgot the lengths I used.
    4) and one more thing... Having taken laboriously to fit - I ultimately had to switch out my rear rotor for a fresh one to fix some noise I had

  61. #61
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    Unfortunately this brings me back to some of the earlier posts. This vibration propagation is known to be an issue with Avid brakes. This is a hard beast to fix. I had some Codes that did this like crazy and I switched out all kinds of stuff attempting to fix the problem, but in the end it has to do with frequency and the caliper design may be contributing. You can switch out pads, grease the back of pads, switch out the rotor, switch out the bolts, switch out the mount, and you may not solve the problem. I was able to solve this problem eventually on my bike by switching rotors and pads, but it's a crap-shoot. One combo I switched to did not work. You're literally shooting at random here and hoping it will work. I don't ever see this problem with any other brakes, or at least it's an ultra-rare occurrence. Take nearly any other brake and go through the same process, it wouldn't be doing this. I know it's been said, but check over EVERYTHING again, headset, hub bearings, etc, and my recommendation is to ditch the caliper and get something else. You might even be able to mount up a different companies caliper to the lever, which is not uncommon, but probably best just to get a brand new front.
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  62. #62
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    Check this out.
    http://cdn.sram.com/cdn/farfuture/up...r_mounting.pdf

    This is a configuration table showing how SRAM thinks you should be doing each supported combination of mount standard and rotor size.

    OP, I'm not sure if you've done it as written yet. Definitely try that if not.
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  63. #63
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    Quote Originally Posted by AndrwSwitch View Post
    Check this out.
    http://cdn.sram.com/cdn/farfuture/up...r_mounting.pdf

    This is a configuration table showing how SRAM thinks you should be doing each supported combination of mount standard and rotor size.

    OP, I'm not sure if you've done it as written yet. Definitely try that if not.
    LOL... I posted that link on my edit. Thanks, though. Looks like I might need to put the washers in a slightly different order.

    Quote Originally Posted by Tweakophyte View Post
    - Do I need shorter bolts? If so, what is the next standard size down? I was surprised I still had to use the CPS washers to mount the calipers. *** Edit: The CPS Washers are part of the setup. Found this on Avid website. ***

  64. #64
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    Quote Originally Posted by bad andy View Post
    ...
    2) you can obviously buy avid pads, though there are other options. (Kool stop, ebc, etc.) I've had good experience with truckerco and they are very kind to the wallet.
    ...
    Avid makes steel and aluminum backed pads. Both types seem to be organic/metallic. What about the other brands? What should I look for in any pad?

    Also, are the pads just held in by that pin? I tried to take them off and could not get the pin to slide easily and did not want to force it. (yes, took off the retention piece.) Any other tool needed to swap pads?

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    The pads sit in the open end of a little cylinder. It should be a slip fit that moves easily, but you do have to slide the pads inward to be able to remove them. It can be a bit fiddly and sometimes things stick.

    There should also be a spring clip that presses them out against the pistons. So you need to remove that too.
    "Don't buy upgrades; ride up grades." -Eddy Merckx

  66. #66
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    Help pls! Major front brake shudder in used 2013 Stumpjumper FSR. What would...

    Quote Originally Posted by Tweakophyte View Post
    Avid makes steel and aluminum backed pads. Both types seem to be organic/metallic. What about the other brands? What should I look for in any pad?

    Also, are the pads just held in by that pin? I tried to take them off and could not get the pin to slide easily and did not want to force it. (yes, took off the retention piece.) Any other tool needed to swap pads?
    The pad material is generally a balance between grip/feel vs. pad life. There are a lot of opinions out the, and you may best be advised to choose dependent upon the type of riding you do. This thread has some insights: Sintered vs organic brake pads

    "That pin" you had trouble removing? It's threaded. Once the retention clip is off, unscrew the pin (I think it's a 2mm?) Then you should be able to slide the pads out pretty easily.

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  68. #68
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    Thanks for the links... Kool Stop sintered pads are in the mail.

    Any advice on pushing back the pistons on these 4-piston models? I was thinking I'd to try to save the old pad. When you push on the brake piston with a (plastic) tire lever, does the other one pop back out?

    Will report back shortly.

    Thanks again.

  69. #69
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    Okay... Kool Stop sintered pads in. I cleaned the rotors with alcohol, so did not listen to advice given to replace rotors, however I could feel no grooving at all on either side of the rotor. I used the old brake pads and a flathead screwdrived to push the calipers back in. If it matters, I forget to turn the "contact" adjusted all the way back. It was one turn in. However, there is absolutely no rubbing... very little clearance, but no rubbing.

    I aligned both by eye and by using the brake. I notice no rotor flexing when I brake. I spun the front wheel slowly at first, then quicker to check clearance. As I said above, there is minimal clearance, and no rubbing. That tells me the rotor is not warped.

    Did a brief bedding process yesterday up and down the street.

    During the bedding process I heard the squeak squeak for a while under light braking. Is that the turkey call people complain about? It was not the big of a deal to me.

    After I did the slow bedding several times I turned the speed and length up a bit.

    There is still some very noticeable shudder. It happens toward the end of harder braking at a medium speed. It seemed to minimize as I continued with the bedding process. It's hard for me to tell if the problem will go away as the brakes bed in a bit more. I should also point out the rotor has a more consistent coloring to it now.

    Are there other set-up techniques I should use to fine tune? It feels like I am properly aligned with the rotor, but should I tune up/down with respect to the fork?

    Could the sag of my fork impact this? For example, if I had 10% sag would it make me more susceptible to shudder?

    How do I check the tightness on the headset (as other had mentioned a while back)?

    It turns out the old pads are organics. How would the fact I'm now using sintered impact this whole ordeal?

  70. #70
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    Check out the brake time forum. A guy fixed his avids by putting tape on the back of the pads.

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  72. #72
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    Having a worn out or very flexy fork can make little problems with brakes into big problems. But they should work about the same throughout the fork's travel.
    "Don't buy upgrades; ride up grades." -Eddy Merckx

  73. #73
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    Hi-

    Quick update. I hurt my hand sparring a few weeks ago and have been unable to ride. Thanks for all the input so far. I'll let you know how long I'm out of action.

    How do I check if my shock is worn out. It doesn't seem to have any play in it that I can tell. Also, how do I double-check the tightness on the headset?

    Thanks,

  74. #74
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    Just want to chime in and say that my front brake had a chudder too. Same spacers were on mine. I tried a lot of different stuff but nothing got all the chudder out.

    Bike is a 2013 Trance 29er with Elixir 3's.

    Reading this thread, I took the advice of putting in a proper spacer.

    Test ride indicates chudder is gone. High hopes thus far. Thanks for the good info... I thought those cheesy little spacers were stock. Or if they are, it's still not right.

    Sent from my HTC One X using Tapatalk 2

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    Hi-

    Glad this thread helped. Are you using a combination of the mounting bracket plus some CPS washers, or just the bracket?

    Thanks,

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    Hi-

    My hand is feeling better, so I spent some time playing around with the brake/wheel last weekend. The shudder is still there, and it happens in a small window of speed and braking pressure. I check the headset... all is firm.

    When I purchased the bike I could look down while the bike was rolling and see a slight wobble in the front tire. The tech said the wheel was true (show me on the stand) and that it was the tire bead that was slightly off. So I deflated the tire and pumped it up slowly, squeezing the bead each to to make sure it was evenly set. Now I am thinking the wheel is slightly out of true.

    There is a chance the brake rotor is not true as well. It was hard for me to tell, but in messing with the mount of the caliper, there was some mountings that I could get a very slight intermittent rub.

    The problem is the shudder does not seem to be in sync with the potential true-ness of the wheel or rotor. How much do you think this could contribute to shudder. It would have to be setting of the right resonance or something.

    How much does it cost to true a slightly out-of-round wheel?

    Thanks,

  77. #77
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    It's very easy to check if your wheel is true, just spin it up while the bike is in a stand and use a screwdriver or other object and hold it 1mm away from the rim edge while the wheel spins. Any wobble or hop will be easy to see.

    That said, I'd expect that your issue with shudder is not to do with the true of the wheel (clearly any issues with the rim do not effect the rotor).

    It is pretty easy to change the rotor front and rear to see if the issue stays. After that, swap the pads front and rear and report back.

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    ^I wrap my hand around the fork leg and hold my thumb next to the rim while spinning the wheel. No scraping or gouging gonna happen from a thumbnail!

    I don't mean to dismiss your advice Skiwi...

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    Tweak, have a look at this thread...I didn't read all, but it might help you.

    My fidings on the Turkey Warble Noise.

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    Quote Originally Posted by jochribs View Post
    Tweak, have a look at this thread...I didn't read all, but it might help you.

    My fidings on the Turkey Warble Noise.
    Hi-

    If I was getting a squeak or a vibration I might try it. I could be wrong but I think this is different. We know it was originally caused by the calipers being incorrectly mounted (too far away from rotor). This issue was only for there for a short while, but it was there for two, long, downhill runs. (note, the brakes were newly mounted when I picked up the bike.)

    The bike was a rental, so there could be other issues that weren't detected or properly repaired.

    - I've played with the headset. It does not seem loose to me.
    - I've taken the wheel off the fork. It's pretty hard to get it back to the perfect alignment, which makes me wonder if it has been run too tight. If the front wheel was (and is) too tight on the fork, would it have damaged the fork or wheel bearings in some way that contributes to this?
    - The front wheel is slightly out of true. No spokes seem to be over tight or loose.
    - The front rotor might be a little out of true.

    Yes, I have some easy debugging to do before I suck it up and bring it in to a shop. Between family and work, it's too bad I only have small windows of time to work on this. Bike is still a lot of fun, though.

    Any comments on the wheel tightness?

    Thanks,

  81. #81
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    Quote Originally Posted by skiwi View Post
    It's very easy to check if your wheel is true, just spin it up while the bike is in a stand and use a screwdriver or other object and hold it 1mm away from the rim edge while the wheel spins. Any wobble or hop will be easy to see.

    That said, I'd expect that your issue with shudder is not to do with the true of the wheel (clearly any issues with the rim do not effect the rotor).

    It is pretty easy to change the rotor front and rear to see if the issue stays. After that, swap the pads front and rear and report back.
    I might try at least taking the front rotor off and seeing if it lays flat. The rear is great, and there's no way I'm messing with it! :-)

    By the way, I've already double-checked the front rotor was properly tightened.

  82. #82
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    ... and it looks like my fork is part of this recall ...
    Quote Originally Posted by mayonays View Post
    FYI, FOX announced a voluntary recall for some 2013 Evolution series forks today. Model Year 2013 Evolution Series Voluntary Recall | FOX

  83. #83
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    ... a little bit of a cross-post (way too many dimensions in this forum!).

    As part of the recall they will upgrade the '13 CTD damper with a '14 CTD damper.

    They also offer an upgrade to the '14 FIT damper for $100 (versus the standard $250). Labor would be covered by the recall.

    Is this worth it?

    PS What is the basic difference between the Float and the TALAS? If I read a review of the '14 TALAS am I essentially getting a review of this upgrade to FIT?

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    Quick update...

    Got the '14 FIT damper installed on the bike. I've only tooled around in the parking lot, but I like it.

    **** Big warning to those moving from calipers that require a full CPS washer set-up to a standard one... When I brought the bike in the shop, the tech pointed out my rear calipers were improperly installed (too high again). AS soon as he put the bike up on the stand, I saw it, grooved pads and all. What's interesting is the rear brakes were performing well (note my two initial downhill runs at Vail).

    He remounted the caliper and left the grooved pads on. The rotor is not grooved (stock organic pads). Rear brakes seem to work fine... no tickles, squeaks or chirps.

    Front wheel was trued ($10)

    Now to the shudder....
    * I took the front rotor off. It was slightly warped, so I played around with bending it... not sure if it made a difference. Still, the front brakes seem better. I put new, semi-metallic pads on with the thought the pads would grind/smooth the rotor. The shudder is still there, and it happens in an ** even smaller window of speed and braking pressure, so I am getting close.** Again, this is initial impressions in the parking lot.

    Are rotors typically true? One add on EBAY for the HS1 rotor said all rotors are out-of-true when the come from the factory. After a few rides, this goes away. Does that sound right?

    Here's what I have left to do:
    - lightly sand the rotors
    - Try the middle-level TruckerCo pads (semi-organic... not full semi-metallic).
    - Maybe replace the front rotor (but will it be true?)
    - quit seeking the shudder and just ride.

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