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Discussion Starter · #1 · (Edited)
I may have a cheap solution for pretty much any brake squeal problem.

It's called CLD (constrained layer damping) tape made by 3M. 3M part # 2552. It can be bought for about $16 a roll through Grainger. It is simply a foil tape with a thin layer of visco-elastic material attached to it. It pretty much sucks up any resonant vibration that could potentially be transmitted to the caliper(s).

Simply cut two small square pieces and punch a hole in the middle of each piece and place between the caliper & caliper mount interface where it screws together. I used a paper punch for a clean hole. This can even be applied between the rotor/hub interface, but so far it hasn't been necessary. Make sure to apply it, burn the brakes good in the driveway, then re-tighten to torque spec as the tape will compress slightly.

I've used this on 3 different major squealer bikes of my own including a 2013 Stumpjumper Evo 29er, and also some of my riding buddies scoots. So far, tested & works on front or rear, Avid or Shimanos, post or tab mount. It has worked perfectly. Of course I can't guarantee it will work for every situation, but I'm guessing it will for most. I had already tried the following on my Stumpy with only temporary good results at best: changing brand/type of pad (Avid, Shimano, TruckerCo), sand & clean rotor (tried with IPA & brake clean), wash & torch brake pads, bleed system, re-align rotor by eye, wrap old tubing around chainstays, add light coat of grease to pad backing. You get the picture. In the end, the damping tape solved the issue immediately. The brakes, to me, even modulate better with the tape in place.

A good cleaning of your rotors, pads, & calipers is still a must occasionally to get good stopping power.

 

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Nice, awesome idea. I'm wondering if the slight compressibility of the tape would necessitate a slightly higher torque. Post mounts and IS mounts are generally relatively strong and tolerant of higher torque.
 

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Magically Delicious
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I wouldn't recommend over torqueing as a result of incorporating a compressible under the caliper. The specified torque is based on the coefficient of friction for a given fastener. That wouldn't change because of a compressible material installed. What I would do is torque to specification and re-check the torque at some later period in time.
 

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This is interesting, as every fix i've read about involves either messing with the pads and/or rotors, never the caliper or mounts. I tried the regular foil tape on the pads, didn't work. Bought a $5 bottle of brake quiet, worked like a charm. How did you figure out this solution?
 

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Discussion Starter · #6 ·
I wouldn't recommend over torqueing as a result of incorporating a compressible under the caliper. The specified torque is based on the coefficient of friction for a given fastener. That wouldn't change because of a compressible material installed. What I would do is torque to specification and re-check the torque at some later period in time.
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Discussion Starter · #8 · (Edited)
This is interesting, as every fix i've read about involves either messing with the pads and/or rotors, never the caliper or mounts. I tried the regular foil tape on the pads, didn't work. Bought a $5 bottle of brake quiet, worked like a charm. How did you figure out this solution?
Brake Quiet is essentially doing the same thing: damping vibrations that would normally be transmitted to the pads. Brakes can only squeal when there is pad/rotor contact. Damp the vibration being transmitted to one or the other and you eliminate the problem. I prefer to damp the static part which in this case is the caliper body. Pads & rotor are both dynamic elements of the braking system so I leave them alone.

I thought about changing the caliper adapter material to something with super damping characteristics, like tungsten, but that increases the weight dramatically. There is a saying in the world of mechanical design: "Light, cheap, and strong. Pick two."

Of course, if simply wiping the dust off your rotor, etc. solves the problem then go with it. Simple is good.
 

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Discussion Starter · #9 ·
I'd be interested to hear how this works, or doesn't work, out for anyone who tries it. I have some other ideas rolling around in my head also, but this one appears to work so why mess with it.
 

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Magically Delicious
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This is interesting, as every fix i've read about involves either messing with the pads and/or rotors, never the caliper or mounts. I tried the regular foil tape on the pads, didn't work. Bought a $5 bottle of brake quiet, worked like a charm. How did you figure out this solution?
I have thought of using the liquid 'Brake Quite', but never thought seriously about doing it. Just installed XT's and that was the end of my problems. Glad to hear that it worked.
 

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Good solution shredz777. I went the "sell avid 2 part HSX $50 rotor, and replace with $11 alligator Wavy rotor" solution. Silence is golden! Note: The one piece Wavy rotor is not as bling as the fancy schmancy 2 part aluminum, but looks good with black bolts. This is for XT brakes that vibrated through frame on small Hardtail.
 

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Discussion Starter · #12 ·
so yesterday, after months of no squealing, the setup on my stumpjumper 29er started howling like a crazy beeyotch, both front & rear. I was riding on some heavily packed trails, but very dry & dusty when the squealing came back. for the record, the setup is XT calipers/levers and Icetech rotors front & rear. 203mm up front & 180mm in rear. TruckerCo superlight alloy w organic semi-metallic pads. When I got home I cleaned everything thoroughly with a light water rinse and they still squealed, even just casually riding in the street. So I busted out the CRC brake cleaner and hit the rotors & pads, wiped down the pistons, reassembled & checked torque on everything, and bled the front which needed it anyway. No dice... The rotor surfaces are in good condition and the pads only 4-5 rides on them. I replaced the damping tape with fresh pieces and the squeal was reduced, but still loud as hell. sigh....
 

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I like this idea and sorry to hear that it may not be as permanent as hoped (at least in it's current configuration).

I had/have similar idea as I discovered (accidentally) when unbeknownst to me my adapter bolts came loose on my rear. During my ride which the trail conditions were wet/sloppy/muddy, I noticed my front very noisy, but back quiet. Didn't know why till I cleaned up bike the next day. That gave me the idea of placing isolators either on the caliper bolts or on the adapter bolts. isolators would be some type of rubber spacer type thing.

Right now I am trying out the aluminum tape on back of my pads and so far so good. Have only tested on road so far, but going to test on trail tonight. Will post results. Keep up the good work.
 

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Discussion Starter · #14 ·
I have another set of wheels that I purchased recently to setup as my urban assault wheels for commuting to/from work. I ordered some Alligator "wavy" type rotors from Pricepoint for them because they were super cheap and had decent reviews. I may try them on my existing wheels when I get them next week.

There is something about the 2-piece construction and laminate rotors on the Ice-Tech's that has me wondering if they may be the problem on my setup. I'm going to try heavily wrapping the fork leg & chain stay on the brake side with rubber tubing as an experiment and see if changing the natural frequency of the frame does anything. A crappy solution, but I'm very curious.
 

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After 2 months with brake quiet, still no squeal, even after a long downhill. I have BB7's with Hayes V6 1-piece rotors 160mm F/R.
Keep working at it, the first one to solve this issue permanently will be a rich man.
 

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Discussion Starter · #16 ·
I got my new Alligator wavy rotors on Sat & installed them. Went on two 15+ miles ride over weekend and not a single peep out of them. Quiet as can be and have great stopping power.

After more inspection on the XT Icetech rotors that were squealing I noticed they were getting pretty thin. Can't believe I put that much wear on them already. So, there's a good chance that the Icetechs were just worn out, but I'm not going to drop $100+ on another set just to find out when the Alligators do the job for 1/3 the cost.
 

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Discussion Starter · #17 ·
So here I am, back again to post that my brakes are squealing again. Recap: 2013 FSR Stumpjumper Expert Carbon EVO 29er w/Shimano XT discs, 203-F 180-R.

I took a trip to MT in early July and damned if my brakes didn't start squealing again. I went through all the cleaning, etc. and that helps only for about 10-15 lever squeezes before the terrible vibration & howling start in the rear end. SH*T!

So... I took the bike in to my Speshy dealer (again) and was told that I needed to replace the seat stay in the rear with one that Specialized came out with recently as a fix. Same exact stay, but the brake side tube on the seat stay is wrapped with carbon material before they powder coat it. The carbon is supposed to damp out the brake induced vibration & thus the squeal. FYI, Spesh was originally replacing these seat stays with a full carbon S-Works stay, but apparently that was getting expensive for them.

Since I bought my bike used (from a guy that was selling it because of the brake issue), Spesh wants me to pony up $240 for the new seat stay with no guarantee that it will fix my issue.

Before I buy the stay, I have tried filling the tubes on the existing stay with Great Stuff expanding foam which helped a little, and I also removed the brake hose clamp that was fastened to the stay which helped a "little" more.

This is really getting tiresome. I saw one of the carbon wrapped seat stays at my LBS & the thing is so ugly with the pregnant guppy look on the tube that the brake boss is on and its powder coated gloss black (my frame is a matte gray/black look). I normally don't care about looks, but this thing is going to make my $6200 ride look like total sh*t. Can't believe this is Spesh's fix for such an expensive bike.

End of rant.
 

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Discussion Starter · #20 ·
$240 is more than the cost for a set of XT brakes (the common proposed solution)

Just sayin'
I know my post was long, but I did mention in the first sentence that I'm running XT brakes already. That was one of the first things I tried. XT's with Ice Tech rotors & XT finned pads.
 
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