Avid Brake Vibration

[driseley]

I have stumpjumper 2010, bought second hand, but in perfetct condition. Spent the last 6 months trying to stoop the rear brakes vibrating the life out of the bike. I have seen a few threads about this, so thought I would post my fix, as I have solved the proble.
Went through all the standard stuff, new pads, different rotor, tensioned spokes and checked rear bearings.
Final fix was to even up the axle length on the braking side, as the axle was uneven favouring the non-braking side. At the same time I replaced the rotor with the newer Avid HS1, and reduced the rotor size from 185mm to 160mm.
My braking is now sweet, and still have heaps of power even with the smaller rotor.
Hope this may help someone else who has similiar issues.

 

[rider124]

We have had Many cases of bikes coming into my bike shop with vibrating brakes.
Many times has been because rotor isnt tight or just replacing the brake pads fixed it,
never heard of uneven axle length causing vibrating?

 

[driseley]

We have had Many cases of bikes coming into my bike shop with vibrating brakes.
Many times has been because rotor isnt tight or just replacing the brake pads fixed it,
never heard of uneven axle length causing vibrating?

Thanks for the response.
Can't say for sure that the axle length had anything to do with the fix, but this and the rotor change was done at the same time, so thought it was worth noting as it costs nothing to adjust the axle. Tightening bolts and changing pads didn't fix my issue.

 

[Lard]

I'd say the axle length had nothing to do with it, it would be the rotor change that did it. I changed from stock avid rotors to hope floating rotors and my vibration problems were over.

 

[redbruce]

I have stumpjumper 2010, bought second hand, but in perfetct condition. Spent the last 6 months trying to stoop the rear brakes vibrating the life out of the bike. I have seen a few threads about this, so thought I would post my fix, as I have solved the proble.
Went through all the standard stuff, new pads, different rotor, tensioned spokes and checked rear bearings.
Final fix was to even up the axle length on the braking side, as the axle was uneven favouring the non-braking side. At the same time I replaced the rotor with the newer Avid HS1, and reduced the rotor size from 185mm to 160mm.
My braking is now sweet, and still have heaps of power even with the smaller rotor.
Hope this may help someone else who has similiar issues.

Not sure you have any evidence to support your theory about axle position being the root cause of the shudder. Not only did you change two other aspects that have been well documented as contributing solutions, there is no fundamental engineering theory to explain it.

Maybe you could readjust the axle back to the original offside position with the current upgraded rotor to verify.

 

[Patchers]

perhaps for the sake of science maybe whack on the old rotor but with the evened axle lenght? Sure is an interesting development. If i had to guess i'd say the change in rotor patter + size did the the trick.

 

[finksta]

I'd say the axle length had nothing to do with it, it would be the rotor change that did it. I changed from stock avid rotors to hope floating rotors and my vibration problems were over.

Yep, same here. Changed the stock rotors on my elixir cr's to some hope floating rotors, vibrations cured as well as the annoying avid "turkey gobble"