Howling Rear Juicy 7's

[TDUB]

My Juicy 7's howl in the rear like crazy with moderate braking going downhill and its driving me crazy.

Here is a list of things that I have done to try and fix this:

• Tried changing brake pads to new Avid pads.
• Cleaned pads with rubbing alcohol.
• Checked and straightened rotors.
• Replaced whole rear brakes setup to new 2008 Juicy 7.
• Re-aligned many times.
• Most recently changed froma semi-metalic pad to an oragnic pad. Right before VQ

My brakes still howled like crazy during my attempt at the VQ.

My Original brake setup came off of a Weyless XP. I cracked that frame and performance replaced it under warrantee with a Fuji Adventure Hi Frame. The howling started after the frames were switched.

This is driving me nuts and the LBS doesnt seem to know what to do. Thanks!

[CalEpic]

Have the tabs on the frame been faced?

[TDUB]

What do you mean by tabs being Faced?

[stinkyrider]

Originally Posted by TDUB

What do you mean by tabs being Faced?

Someone please correct me if I am wrong but....
I think that's when the tabs are resurfaced to make sure that the tabs are completely flush and plumb. Sometimes there are miniscule factory defects or the paint coating itself can put the tabs microns off of being fully flush that can cause minute deviations from the proper angle at which the components should be. The minor deviations can effect the performance and wear on your components especially parts like the bottom bracket.

From what little I know, when they "face" it, only fractions of a milimeter are shaved off with a special shop tool

[tkblazer]

i had the same prob when i transferred my J7s over from my reign to IH frame... had Adrenaline face the disc tabs and all is well now

[DeeZee]

Originally Posted by TDUB

My Juicy 7's howl in the rear like crazy with moderate braking going downhill and its driving me crazy.

Here is a list of things that I have done to try and fix this:

• Tried changing brake pads to new Avid pads.
• Cleaned pads with rubbing alcohol.
• Checked and straightened rotors.
• Replaced whole rear brakes setup to new 2008 Juicy 7.
• Re-aligned many times.
• Most recently changed froma semi-metalic pad to an oragnic pad. Right before VQ

My brakes still howled like crazy during my attempt at the VQ.

My Original brake setup came off of a Weyless XP. I cracked that frame and performance replaced it under warrantee with a Fuji Adventure Hi Frame. The howling started after the frames were switched.

This is driving me nuts and the LBS doesnt seem to know what to do. Thanks!

Are you using clean sweep rotors?

[2wheel_lee]

I've typically experienced howling on new brakes/pads/rotors. Maybe they just need to be broken in. It took a little while for the brakes to break in on my DH bike, but since that time, they've been silent.

The Hayes on my singlespeed, on the other hand, just recently started squealing for no good reason after 4+ years of silent use. I haven't looked into it yet, though.

[Zippy]

If you mean the Turkey "gobble" then it's just normal for the rotor and many people I've talked to have that problem, me included. If it's a loud squeal, I fix it by the steps you've already mentioned. Maybe turn your headphones up?

[nintense]

No need to re face anything with the Juicy, you can align the caliper by slightly loose the bolts, put a business card between the rotor and the pads (both sides), and squeeze the lever. While the lever squeezed, tighten the bolts.
If it still noisy, get a kool stop pads.

Good Luck

[TDUB]

To my knowledge the tabs have not been faced. That is something I will look into. Do they do this at the LBS?

Yes I am running the cleansweep rotor. It came with the new rear setup.

[DeeZee]

Originally Posted by Zippy

If you mean the Turkey "gobble" then it's just normal for the rotor and many people I've talked to have that problem, me included. If it's a loud squeal, I fix it by the steps you've already mentioned. Maybe turn your headphones up?

Many folks have cured the dreaded gobble by swapping rotors. The 2nd pic is the clean sweep rotors

[CalEpic]

As mentioned above, facing the tabs aligns the caliper mounting position so that it is exactly 90* with the axle. When it's not, the pressure on the pads are not uniformly distributed and creates hot spots that affect performance and often results in squeeling.

As Nintense mentioned, often the business card trick works with post mount set ups. For I.S. mounts (which almost all frames use) you'll still need to properly shim the caliper whether the tabs have been faced or not.

Most shops can face the tabs quickly and inexpensively.

[TDUB]

I have the rotor in the second picture which I believe is the cleansweep rotor.

The noise is very loud. People here me coming and get out of the way(only good thing about it!)

I have tried realinging the calipers many times following the avid directions, but never using the business card method.

[nintense]

Originally Posted by CalEpic

As mentioned above, facing the tabs aligns the caliper mounting position so that it is exactly 90* with the axle. When it's not, the pressure on the pads are not uniformly distributed and creates hot spots that affect performance and often results in squeeling.

As Nintense mentioned, often the business card trick works with post mount set ups. For I.S. mounts (which almost all frames use) you'll still need to properly shim the caliper whether the tabs have been faced or not.

Most shops can face the tabs quickly and inexpensively.

And rounded spacers for 3D alignment.

[TDUB]

The spacers that i use are rounded style.

At some point im just wondering if my style of braking is causing the howling. I weigh about 200lbs so I am constanly on the brakes trying to keep my speed from getting away from me.

[DeeZee]

Originally Posted by TDUB

The spacers that i use are rounded style.

At some point im just wondering if my style of braking is causing the howling. I weigh about 200lbs so I am constanly on the brakes trying to keep my speed from getting away from me.

No it is not you. My Hopes squeeeeeeeeeeeeled like crazy on one frame and then on another frame they were silent.

You have done everything else except facing (as others have suggested). Give it a try

[Bryguy17]

judging by the fact that it started with a frame swap, and the normal (and pretty much all) remedies have not fixed it, i would put my money on resonance. All brakes have a certain frequency that they vibrate at. perhaps the juicy's frequency matches the resonant frequency of the frame, amplifying the sound to obnoxious levels.

try changing the rotor size if you can borrow a rotor/adapter from someone, as that would change the frequency put out by the brakes, and possibly get rid of the resonance. i know for a fact the the cleansweep rotors don't get rid of the gobble. happens all the time on my bike

[Rossage]

I agree with Bryguy. I had gobble issues on my 575 ever since I tried bigger rotors to get more power. The gobble perisisted through Juicy 3's, 5's and Codes untill I went back to a 160 rotor and since then-no gobble, no vibration-nothing. Maybe a frame/resonance/vibration thing

[dfioc]

I had the gobble squeak with the Juicy Carbons on my XC bike and the only thing that fixed was to switch out the rotors from Cleansweep to XTR. No probs now. My main riding buddy had to switch to XT rotors to fix the problem. Interestingly, the 7's on my trail bike have performed flawlessly with the Cleansweep. Go figure.

[TDUB]

Ok im going to look into getting the mounts refaced. As for changing rotor size should I go down or up in size? And should i stay with the avid rotor or should i try another brand? I currently have 185mm on the rear.