One of my BB7s has recently started squealing when not braking. It seems that the outboard pad doesn't sit square when the brake isn't applied and so one edge of it lightly brushes the disc. Applying and releasing the brake sorts it out for a few seconds as the pad squares up, but it keeps coming back. I've tried replacing the pads, but that's made it worse. Backing off the pad adjuster doesn't seem to make much difference.
I can't work out what's up with it. It seems like the end of the piston is designed to have a bit of play in it, but I can't see why the pad isn't sitting square. The spring is now brand new, and seems to be in good shape. Any suggestions?
mine does at times. Strip, clean, realign.
Still happening? Is the wheel straight? Open the QR and close with the bike on the ground.
Through axles? No bloody idea.
Yeah, I'm used to BB7s being a pain to get the pads close enough that they work, but not so close that they rub.
This seems to be a different problem, as I can back off the pad loads and I still get rubbing, seemingly because one pad is at an angle once it's not touching the disc.
The end of the piston seems designed to move around a bit. I'm wondering if it's supposed to be a bit stiffer, so that it only changes position when the brakes are applied, and then stays at the same angle when released.