Baer Pro+ / 6P Caliper brake pad 'noise' question

[carbuff]

Is there anyone out there who is running the Baer 6P caliper (in my case part of the Pro+ kit) with aftermarket / non-Baer pads? If so, do you have any kind of noise problems with them?

I replaced the Baer pads earlier this year with a set of the Hawk HP+ pads. They squeal some, I expected that. They dust up the wheels more, I expected that. But I think the pads are rattling (for lack of a better description) inside of the caliper. This I didn't expect.

The symptom is that I drive down the road, and I get a slight speed-dependent clunk from the rear. I've been banging my head against this for a while. It's been suggested that this could be a flat spot on the tires, but it sounds much more mechanical than that.

Well, the other day I finally realized that if I put the car in neutral (to get the exhaust quiet enough to really listen), and I started rolling (which is when I can really hear the noise), if I touched the brakes lightly, the clunk stopped. I've done this several times now, and it seems to consistently go away with a very light brake application.

Today when I had a wheel off, I grabbed the little tab in the center of the backing plate, and I can wiggle the pad up and down (with the caliper oriented vertically, so it's moving along the arc of the rotor). When I do, it will make a noise as it hits the caliper body top and bottom. So I'm surmising that friction from the rotor spinning may be causing the pad to move when no pressure is applied, and the contact is the "cluck" I hear.

I do not recall hearing this with the original Baer pads. Unfortunately I don't have time at the moment to swap them to experiment, but I will try to do that soon. These calipers use a C5/C6 backing plate, so it's nothing unusual I'm sure!

Has anyone else experienced this? This cluck is one of the last odd noises that I'm trying to cure.