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  1. #1
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    Brake vibration resonance. has anyone got long term fix?

    Wanted to start a new thread on this.

    and I want to clearify that this is NOT your regular everyday squeek or turkey noise that most all brakes make a little of. This is a wicked vibration from the rear brake that resonates throughout the entire bike up to the handlebars. sounds like a fog horn. I have had this issue on my 2010 Stumpjumper FSR comp26" for the last two years. I have tried EVERYTHING including ditching the Avid brakes and installing a set of Formulas. different pads, size rotors, different type rotors (even tried the solid rotor)

    I am convinced that this is an issue with the frame. and it seems to happen after the pads have fully seated in. I have tried different things over and over and the noise/vibration will go away. but eventually comes back after the pads bed in. I was wondering if anyone has had the same issue ...again, this vibration resonance not just squeek. and if anyone has had a long term fix.

  2. #2
    old fart
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    Check the pad wear. Is it uneven or otherwise odd? If it is then it could be an alignment issue.

    The other thing I would check is your rear wheel. Are the bearing OK, and it is running true? When under braking pressure, the wheel could be causing the rotor to run out of true.

  3. #3
    DynoDon
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    It seems the only thing you haven't considered is contamination, I'd reccomend Finish Line Ceramic Wax, don't laugh, this is the least contaminating lube system I've found, it doesn't take much, most of it dries up leaving your chain lubed with ceramic lube, its fairly new, last way longer then wax, I'm not sure why they call it wax, it sure is clean, very little build up, nothing like other waxes. Make sure to keep it off your rotors. Good Luck...
    Four wheels transport the body,

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  4. #4
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    Quote Originally Posted by skiwi View Post
    Check the pad wear. Is it uneven or otherwise odd? If it is then it could be an alignment issue.

    The other thing I would check is your rear wheel. Are the bearing OK, and it is running true? When under braking pressure, the wheel could be causing the rotor to run out of true.
    I know you guys are trying to help, but please understand. I have probably changed the pads 10 times on this bike (6-8 avids and then switched to Formulas) I have put about 2000 miles on this bike. I have two completely different wheelsets. I have lost count how many times I have aligned the caliper (50?) I have switched the entire brake system from avid to formula and the exact same vibration comes back no matter what I do. I know other people have been through something similar with specialized and I hope you will chime in.

  5. #5
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    for example: I went to my LBS (thanks guys here in temecula for trying!)

    and we tried a diffent size brand new rotor. the noise/vibration only changed slightly in pitch. we tried diffent pdas. alignment. cleaning. everything. we wrapped the chainstays with foam and weights.

    The only thing that has helped is wrapping the upper seats stay to the lower chain stay with an inner tube so that the two are pulling against each other. this seems to be a 50% fix but is extremely ugly. I have also changed all the suspension piviot bearings (lower near the crank was siezed after racing in the rain and mud) I even filled the frame stays with expanding foam. I don't think there is anything I hav not tried, and so I already have gave up to tell the tuth. I am already shopping for another bike. I just would like to fix this one someday, somehow.

  6. #6
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    You need to file the edges of the brake pad lining, clean and lube the backing plate and piston, go out an ride.

  7. #7
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    Dude, I know your pain, however, I didn't change 20 sets of pads and brake sets. I had this exact problem on my 2006 Demo 8 with Saint brakes and your right about the pads bedding in and then it happens- honking, shuttering vibration through the entire bike. Then I sold the Demo 8 for the 2007 Demo 7 and guess what, the vibration jumped from the old bike to the new one! I've had a few sets of pads but nothing worked. So I live with it. I almost wish that the calipers had a vibration damper like a tennis racquet.
    A few things that helped: SPARINGLY GREASE the contact points of all metals in the braking system. This includes between hub and rotor, rotor and bolt heads, caliper bolts and frame, the back of the brake pad and the piston. So obviously you will néed thicker grease so it stays put and helps with vibration dampening. This tip was passed to me by the best mechanic I know and it helped the most ( the problem was much quieter). I know it sounds crazy to get grease anywhere near your pads and rotors, be careful not to contaminate things if you put to much the heat will cause the grease to run out cnd contaminate the pads. Hope this helps...
    Oh here's something I haven't tried- o rings from the hardware store, try one under the caliper bolt head and one between the frame and caliper, not to thick. The idea is to help the stop the resonance from traveling up the frame.
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  8. #8
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    I didn't see any mention of cleaning the build up from around the pistons which can cause them to not move freely or in EXACT unison. This is what causes that horrifying back brake resonance for me with Magura Marta SL brakes. But once I do the proceedure and free up the pistons, the issue is resolved or at least minimized until build up once again causes the pistons to stick/freeze up.

    I also find that a little hard braking on the rear to heat up the rotor seems to stop the resonance if/when it starts up.

    There could also be a little air in the system or weak/worn out fluid.

    It was also recommended by a Magura rep to have the brake tab(s) machined to provide a perfectly flat contact point where the caliper bolts on.

    There an article in the newest MBA magazine about doing this proceedure on your calipers.

  9. #9
    DynoDon
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    If your anywhere Michigan bring the bike into our shop, our head mech has been there since he was 13 yrs of, he's near 50 now, we are a Specialized dealer, if he can't figure it out it can't be figured out, Town N Country in Livonia, Mi near Detroit, we are far from a high tech shop, more old school, a real bike shop, we don't sharpen Hockey skates, we don't sell anything other then bicycle stuff, we fix ****, if we can't it can't be fixed. I will be warranteed, Otto is there on Mon, Tues, and Wensday, we ride bikes, we have the passion, let a pro look at it, or keep Paying peanuts and getting monkeys.
    Four wheels transport the body,

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  10. #10
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    Quote Originally Posted by ambassadorhawg View Post
    I didn't see any mention of cleaning the build up from around the pistons which can cause them to not move freely or in EXACT unison. This is what causes that horrifying back brake resonance for me with Magura Marta SL brakes. But once I do the proceedure and free up the pistons, the issue is resolved or at least minimized until build up once again causes the pistons to stick/freeze up.

    I also find that a little hard braking on the rear to heat up the rotor seems to stop the resonance if/when it starts up.

    There could also be a little air in the system or weak/worn out fluid.

    It was also recommended by a Magura rep to have the brake tab(s) machined to provide a perfectly flat contact point where the caliper bolts on.

    There an article in the newest MBA magazine about doing this proceedure on your calipers.
    I've got a 2010 Stumpy with Avid's and started having the same problem after I changed out the stock pads on the rear. I bought metallic pads thinking that's what was originally in there but they turned out to be organic. After the pads bed in, I started having a crazy vibration. Cleaned the pistons as indicated above and the problem mostly went away. It's kind of a PITA, but well worth the effort.

  11. #11
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    I have exact problem on my Enduro '11 with Shimano SLX 2012 brakes.

    I didn't have any problem while I have 160 rotor at the rear (smrt76) and after some time I changed 160 rotor for brand new 180 (smrt76) rotor.
    After first ride everything was great and on the second ride at the middle of the trail the whole bike was start to vibrate.

    After that every ride is the same soon i hit rear brake. I tried everything but still no improvement.

    Last option to try is to change back to 160 rotor to see if it's gonna happend again and i will try with Hope SAW rotor.

  12. #12
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    Quote Originally Posted by CarlS View Post
    I know you guys are trying to help, but please understand. I have probably changed the pads 10 times on this bike (6-8 avids and then switched to Formulas) I have put about 2000 miles on this bike. I have two completely different wheelsets. I have lost count how many times I have aligned the caliper (50?) I have switched the entire brake system from avid to formula and the exact same vibration comes back no matter what I do. I know other people have been through something similar with specialized and I hope you will chime in.
    I hear you, but you're not hearing me. I said have you checked the wear pattern on the pads? If one is wearing more than the other, you have a piston issue - sticking or otherwise not working in tandem, or an alignment issue - the caliper not straight (this could possibly be misaligned mounting holes) - or the wheel mounting moving under load.

    Brake vibrations are not rocket science. The brake rotor is vibrating in the caliper and those vibrations are resonating through the frame. Those issues are classically alignment issues, uneven piston activation, or deposits on the rotors.

    Usual rules apply. To paraphrase Sherlock Holmes "Eliminate all other factors, and the one which remains must be the truth."

  13. #13
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    Quote Originally Posted by zgmmax View Post
    . . . at the middle of the trail the whole bike was start to vibrate.
    I haven't tried this but this may work if someone is willing to try.

    The attached photo is a screen shot of anti-squeel products. I will try these on my Formula The One brakes for wet weather use.

    My 911 has a small vibration damper fitted between the pad and piston.

    The point is, WE ARE NOT ALONE!
    Attached Thumbnails Attached Thumbnails Brake vibration resonance.  has anyone got long term fix?-brake-anti-squeal.jpg  

    Brake vibration resonance.  has anyone got long term fix?-brake-vibration-damper.jpg  

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  14. #14
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    You are effectively matching the resonate frequency of vibration of your frame to something on the disc rotor. The rotor needs something irregular in its design to give a pulse to the frame. The 'something' could be number of holes on the rotor contact area or the number of arms that connect the rotor to the hub or even the number of bolts connecting the rotor to the hub. It might be made worse by brake set up.
    A fix is not easy but I would look to change the rotor style dramatically, magura rotor maybe? You could change the stiffness of the rear end by adding a bolt through axle. Have you tried asking specialized?
    When I had this on a enduro 2005 it turned up when I changed to a bolt through axle....

  15. #15
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    Try a solid sweep rear rotor (Avid 3GSS in my case). It worked on my 2011 Stumpjumper 29er Comp. It killed the interplay between the rotor and stays vibration resonance by getting outside of the frequency.

  16. #16
    Mountain Man Dan
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    Quote Originally Posted by John Barrett View Post
    Try a solid sweep rear rotor (Avid 3GSS in my case). It worked on my 2011 Stumpjumper 29er Comp. It killed the interplay between the rotor and stays vibration resonance by getting outside of the frequency.
    He already tried that..........

    I have tried EVERYTHING including ditching the Avid brakes and installing a set of Formulas. different pads, size rotors, different type rotors (even tried the solid rotor)
    The bike is nothing more then circles turning circles, It's the human motor that makes it elegant.

  17. #17
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    Quote Originally Posted by ProjectDan35 View Post
    He already tried that..........

    OK....so it is time for your LBS to really get down and nasty with Specialized.....with clear documentation of EVERYTHING that you have tried. Your bike is essentially un-rideable.....in your opinion.

    There is probably nothing else that anyone here can do to help.

  18. #18
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    My Avids did that on my 2011 Epic 29er, dumped them for Formula R1s and never looked back. Since you said your Formulas do the same thing, I'm beginning to think it's something YOU are putting on them or doing do the brakes. Maybe some form of wash or liquid contamination, or perhaps something in some streams near you that you are riding through?

  19. #19
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    Cleaning rotors with Isopropyl alcohol can often quiet things down.........I've found.

  20. #20
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    FWIW

    I have a '11 Rockhopper SL that used to drive me crazy with the loud rear brake noise that happened every time, everywhere, whenever the brake was operated

    So, being the bike almost new and the owner fed to death with the big time noise that does not fit well with the very silent mountain trails we have here, I took it to a nearby Specialized "Concept store", where the owner, a seasoned expert in the business for not less than 20 years, tried anything including, changing pads, filing the borders os the pads, filing a line in the middle of the pad, changing disk and maybe something else all to no avail.

    When I got the bike back, I started to debug (sorry I am in the software industry) the problem myself discovering that when the resonance was in progress, touching the left seatstay with a foot stopped the noise immediately. That confirmed that the problem was not really in the pad+disk duo but rather in the frame itself.

    What solved completely the problem?? Taping a 40gr lead weight (those used for heavy fishing) in the middle of the left seat stay, with the purpose of moving the frame resonance point away.

    I've put more than 2000km on the bike since then, with no sign of resonance anymore

    happy biking

  21. #21
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    Quote Originally Posted by sneeboo View Post
    FWIW

    I have a '11 Rockhopper SL that used to drive me crazy with the loud rear brake noise that happened every time, everywhere, whenever the brake was operated

    So, being the bike almost new and the owner fed to death with the big time noise that does not fit well with the very silent mountain trails we have here, I took it to a nearby Specialized "Concept store", where the owner, a seasoned expert in the business for not less than 20 years, tried anything including, changing pads, filing the borders os the pads, filing a line in the middle of the pad, changing disk and maybe something else all to no avail.

    When I got the bike back, I started to debug (sorry I am in the software industry) the problem myself discovering that when the resonance was in progress, touching the left seatstay with a foot stopped the noise immediately. That confirmed that the problem was not really in the pad+disk duo but rather in the frame itself.

    What solved completely the problem?? Taping a 40gr lead weight (those used for heavy fishing) in the middle of the left seat stay, with the purpose of moving the frame resonance point away.

    I've put more than 2000km on the bike since then, with no sign of resonance anymore
    happy biking
    Interesting. I have the 2011 Rockhopper SL Expert 29 with Shimano brakes. Quiet as a mouse.

    On the other hand...my 2011 Stumpjumper 29er Comp HT rears screeched like an owl from day one. Went through all of the Avid changes and finally cured the problem with a G3SS solid rotor.

  22. #22
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    I have a 2011 Hardrock with shimano hydraulic disc brakes and it's silent. Squealed once due to lube contamination from the hubs, but became silent when the rear brake rotor was cleaned with dishwashing soap, rinse with water, then isopropyl alcohol. Maybe the heavier, thicker frame is more resistant to brake resonance

  23. #23
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    Yeah, now after almost a year of pain, mine is quiet as a mouse too and it is a *real* delight enjoying the power of disk brakes without a hiss

    I also believe that much of the problem on the rockhopper is due to the fact that the frame is relatively light and thin in some areas, helping this kind of problem together with the use of a low end factory brake system

    Like I said, in my case pad sanding, rounding, notching and even the disk sanding simply had no effect, go figure a simple isopropyl alcool cleaning...

  24. #24
    CS2
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    Quote Originally Posted by sneeboo View Post
    FWIW

    I have a '11 Rockhopper SL that used to drive me crazy with the loud rear brake noise that happened every time, everywhere, whenever the brake was operated

    So, being the bike almost new and the owner fed to death with the big time noise that does not fit well with the very silent mountain trails we have here, I took it to a nearby Specialized "Concept store", where the owner, a seasoned expert in the business for not less than 20 years, tried anything including, changing pads, filing the borders os the pads, filing a line in the middle of the pad, changing disk and maybe something else all to no avail.

    When I got the bike back, I started to debug (sorry I am in the software industry) the problem myself discovering that when the resonance was in progress, touching the left seatstay with a foot stopped the noise immediately. That confirmed that the problem was not really in the pad+disk duo but rather in the frame itself.

    What solved completely the problem?? Taping a 40gr lead weight (those used for heavy fishing) in the middle of the left seat stay, with the purpose of moving the frame resonance point away.

    I've put more than 2000km on the bike since then, with no sign of resonance anymore

    happy biking
    There is a post in the Brake Forum about putting the sinker on the caliper. I guess it's the same principal.
    1982, 1983, 1984, 1985, 1986, 1992 Stumpjumpers. 1995 Waterford 1200, 1999 Waterford RSE, plus a garage full of steel frames.

  25. #25
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    Quote Originally Posted by CS2 View Post
    There is a post in the Brake Forum about putting the sinker on the caliper. I guess it's the same principal.
    The rotors are causing a resonance that is of a frequency that the frame picks up on. Anything that changes the frequency will stop it....

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