Brake Harmonic Frequency

I'll pull it all apart and take a look - if it were something like that, I would expect it to happen all the time though.

Update

I've tried the following:

Parts:  3 different wheels, 3 different rotors, too many brake pads to count, a full tear-down and a new rear triangle

Testing: up&down a local roadway (way too many times to count), homemade rubber gaskets, more grease at interface points and adding weights around the frame to move the frequency away from the rotor.

Findings: I believe the issue is the wheel itself as the vibration only started after this wheel/hub were replaced. I haven't removed the vibrations completely, but it only happened once (very slight) on a recent ride with a different wheel - I haven't been able to replicate since. I have not yet ridden on the new rear triangle, so that will be the final test. I plan to give some feedback to the manufacturer and see if this is a known issue.

What an expensive and obnoxious pain in the ass this chewbacca-chasing adventure has been. Hopefully I've got it sorted now.

It is still happening with the new wheel - but not as frequently...and mainly when I'm dragging the rear brake.

Now I'm wondering about the brake caliper itself...there isn't much else left on the brake-side of the bike to change.

Maybe a worn piston/seal that is allowing the piston to vibrate somewhat? Any chance there might be a crack in the caliper where the mounting bolt goes through?

The seal/piston is an interesting thought - wonder how to check that out. The caliper doesn't have a crack as I did inspect it when re-assembling everything for the upteenth time.

I pushed out the pistons and re-lubed them (a-la-Cam's article) - no sign of damage/wear or cracking. I smack the caliper and don't hear anything rattling - so things are tight. I'm at a total loss.

Two last things; swapped out all the hardware for new (caliper bolts + rotor bolts) and the sound was less frequent.

Final move was to have the brake mounts + adapter re-faced - seems to have done the trick for the most part.

Posted by: Taz123

Two last things; swapped out all the hardware for new (caliper bolts + rotor bolts) and the sound was less frequent.

Final move was to have the brake mounts + adapter re-faced - seems to have done the trick for the most part.

Wow. Epic game of whack-a-mole.