My buddy has a Jekyll that needed some TLC. Well I took up the challenge and went to work. Some people don't like or aren't good at fixing things, but that's not me. Anyway, he complained primarily of bad shifting and ghost shifting. Easy stuff until I rode the bike.

The brake up front (BB7 with 185mm adapter and rotor) shook like a whore in church! I couldn't believe it. As I examined carefully the situation, I realized that the wavy rotor from Avid was fully engaged with the pads at the wave but partially engaged at the trough. This gave a very harmonic and notable pulse which perfectly coincided with the peaks and troughs of the rotor.

I thought that it might be easy to fix. I first tried to move the caliper closer to the rotor, but those special spacers do not lend themselves to being removed. So I thought about facing the adapter to move the caliper closer, so I examined the rear brake which was on a 160mm rotor.

Did anyone ever notice that the 160 has more depth than the 185? Seriously, the 160 engages the pads fully throughout the rotation, so no harmonic vibration.

Well to make a long story a little longer, I swapped the 185 for a 160 swept by Avid and the vibration went away like magic!

There were a few other issues like a frozen chain link and bad end bushings on his Fox rear shock, but not anymore!

Bike rides almost as good as my Prophet.

Cheers, hope this helps someone with the BB7 wobble!