Unbelievable, but true Story - Avid Brake Turkey Warble

OK, some of you will find reasons to deny my claim and others will brag that they knew it all the time. Here is my story. I built up a new Niner EMD and moved my trusty Elixer R brakes over from my stumpy to the Niner. Never suffered brake noise before, but on the Niner...OUCH!!!. The rear brake was so noisy, I was embarrassed to ride it. Now you XT/XTR brake owners can stop reading. This thread is aimed at you Avid users. I started searching the WEB for answers and I got a lot of them. Everybody has an opinion...clean the pads, sand the rotors, replace the rotors, bleed the brake, check for stuck piston, blaa, blaa, blaa. Finally, I found one small comment, from one unknown person, from one small thread, from one obscure website. This person suggested that the brake line can resonate if not securely attached to the frame causing brake noise. I thought this was silly, but I know a thing or two about stuff resonating. You see, I work at the nuke plant down the road and we have a little (well OK a big) problem with resonating steam generator tubes. Yah they are vibrating like a bunch of tuning forks and the engineers are still struggling with the fix. Anyway, I digress. I thought, why not give it a try so I took a piece of electrical tape and secured the brake line to the frame right behind the clip nearest the brake.

Wow, no more brake noise…none! OK, I needed to be sure so after a couple of weeks noise free, I removed the tape. The noise returned immediately! It sounded pretty convincing to me. Still not convinced? OK I rode Old camp this morning, but I forgot to replace the tape. Bummer…I was at the top of Old Camp with noisy brakes, and no tape. So I wedged a plastic bag between the brake line and the frame.

I rode all the way back to Cook with the plastic bag fix in place and, once again, noise free. If you are plagued with noisy Avid’s, give it a try. Hmmm, I wonder if electrical tape would work with faulty steam generator tubes.

 

Excellent I like simple fixes.

Dean

 

My Avids squeal because I suck at riding.

 

I have found my bike laughing at me due to my skills too.

 

Holy radioactive steam, Batman!

That's quite a discovery. I'm curious if it's the brake line vibrating, or if by taping the brake line, you're applying a dampening effect on the caliper. Taping it is like pushing on the caliper with your finger to dampen the vibration, but your shoulder wouldn't get sore from trying to ride in that twisted position.

http://www.findtape.com/product391/Polyken-226-Nuclear-Grade-Duct-Tape.aspx

 

I know the answer to your steam generator problem and don't want to spoil it for you, so I'll let the big boys figure it out....

 

Most Excellent a truly interesting, helpful and entertaining thread bravo!
and hmmm I got a stumpy SS with plenty of brake noise, I will apply the test.

 

No, no, no... That can't be it. That's too cheap and simple. The only way to fix it is to spend $500+ on new Magura XT Formula brakes.

JK. Seriously though, thanks for the tip. I would of never thought of that if I ever had that problem.

 

I just enjoyed the story telling! It was gripping, and funny, and let me right where you wanted me. I give two humbs up!!

 

It may be the fluid resonating. What if you bleed your brakes? (get the air out)

 

I will not say that I would have guessed it, but have seen the problem before in cars. I had a 2003 Mercedes Benz I was working on with this horrible rattle in the cabin that would come and go. Turns out that EVAP purge valve was rubbing on the frame. When the valve was actuating it would resonate through the whole car. Talk about a problem the was hard to find. I spent a whole day fixing that damn thing. Well the fix took 5 min, but finding it took all day. LOL. Thanks for sharing. Its easy to overlook the small things.

 

Now I have to tape down the brake lines on my Mazda.

 

So... does this mean we have to start calling you MacWizard now? Nice find...



- shud

 

^^"Dude, he totally MacWizarded it!"

 

Wizard - THANK YOU!! The Avid Elixir CR brakes that came on my bike howled like a banshee from day one. They worked fine; it's just that they were so noisy they would wake up the dead!. I upgraded to Shimano XTR($$$) front and back and enjoyed a couple of weeks of quiet braking until about three weeks ago. The rear started howling with a vengence as though making up for lost time. PISSED! PISSED! PISSED! I saw your thread last night and did the simple mod. I used a piece of inner tube between the hose and frame and zip-tied the hose in two places instead of just one as is stock. I just got back from a ride up/down Blackstar Canyon and made it a point to ride the rear brake extra hard on the descent. Guess what? Not a single squeak out of the damn thing! Not one! Zip, zero, nada! THANK YOU again!

To follow your line of thinking, I think what happened with the XTRs is that while the single zip-tie holding the hose to the frame was new/tight, the brakes remained quiet, and as the bike was used more, and the sun beat down on the zip-tie, it started stretching/loosening allowing the resonance effect to kick in.

Beers/lunch on me if we should ever meet/ride together.

So, I now have a great pair of Avid Elixir CR brakes with practically new pads begging for a new home. You guys now know how to keep them quiet and happy. Make me a reasonable offer and they are yours.

 

Premature celebration. Coming down Maple Springs this morning the rear brake was in full song again!](*,)

 

Read this: http://forums.mtbr.com/frame-buildi...frame-expanding-foam-lead-weights-618531.html I had this problem with elixirs with my banshee rune. The brakes made the rear triangle resonate. Permatex 'disc brake quiet" sprayed between mounting bracket/rear triangle and a tube wrapped around the seatstay did the trick. Oh and also I swapped out my avid mounting bracket for a Hayes that had different mass and changed the frequency. btw im "dwyooaj" on mtbr. Now i have saints on an sc butcher, quiet.