[dersherwin]

Hi All, new to this thing so forgive any major posting blunders that may ensue.

I am having noise and vibration coming from my rear wheel that I cannot diagnose.

I thought it was the brakes, maybe the pads vibrating against the rotor, so I (1) replaced the pads, and (2) cleaned the calipers (which were very dirty). I cleaned the calipers/pistons with a tooth brush dipped in DOT 4 brake fluid and used compressed air to remove the excess fluid and grime. The pistons moved freely and retracted. Went for a test ride, just as bad as before the servicing.

Here are the symptoms and details:

1) On a bike stand, the rear spins freely and comes to an even, gradual stop.
2) Running Avid Juicy 5. 3 years old, new pads.
3) Rotor is snug to the hub, shows sings of use, but not overly grooved.
4) the Noise ONLY occurs during coasting, and seems to be independent of speed.
5) Noise persists even when I engage the brake with light pressure.
6) Noise sounds sort of like the honk of a goose.
7) Problem is getting worse & at times feel vibration into my cranks.
8) The center portion of one piston is chipped and no longer flat, the outer surface fine.
9) WHole bike FULLY serviced 9 months ago.

Alright, Doctors, that's about all I can think of.
Appreciate your input very much, and may your next ride be your best ride.

 

[smilinsteve]

Only coasting? That means, with the bike in the stand you turn the crank and the wheel spins without noise, then you stop turning the crank and goose starts honking?
That sounds like a freehub problem, although goose honking from a hub is unusual.

 

[Prophet Julio]

I vote for brake issues, sort of. I wonder if your rear wheel is in the dropouts fully. If not, the pressure from your weight will cause the rotor to rub against the pads. On the stand, you can set up the brake to be "perfect", but it is not "true".

Remove the rear caliper, tie it to your seat or something out of the way and see if the noise goes away.

Good luck!

 

[loydfl]

Sounds like an issue I had. Mine was that the freehub pawls were excessively worn and getting stuck. Had them replaced and no more "goose honking"

 

[dersherwin]

Thanks for the thought, loyd.
A friend suggested the pawls - they might need cleaning.
However, the free-wheel effect seems smooth.
Also, I have not tried running the cranks in reverse when the honking starts....that may or may not be an indicator of the pawls.

 

[dersherwin]

Pulling the rear brake assembly off the rotor and taking a test ride is probably another to-do diagnostic - will keep you posted. Thanks to all contributors.

 

[loydfl]

Thanks for the thought, loyd.
A friend suggested the pawls - they might need cleaning.
However, the free-wheel effect seems smooth.
Also, I have not tried running the cranks in reverse when the honking starts....that may or may not be an indicator of the pawls.

Mine spun fine most of the time as well and didn't always honk. Also pedaling in reverse was mostly fine as well. Taking it apart is a really fast way to find out if it is worn or full of junk as that was something I encountered a time or 3 as well before it completely failed.

 

[dersherwin]

Problem Solved

:thumbsup:

For a mere ten-spot, problem solved.
"The hub was bone dry", said Steve, a local mechanic.
Thanks, Steve.

The noise was the pawls rubbing against the free-wheel hub.
So now the cassette is no longer loose, rotor runs true, and rear wheel
is a Whisper.

Ten bucks, sweet. Time to get Steve a box of donuts !

Thanks to all that replied.