Thanks, Frank. Didn't know that.
In racing this is actually a really bad thing. I can see how it would be on the street too if it was taken too far. You can actually buy a 1 or 2 psi checkvalve that ensures that your pads stay against your discs, for use on the track. In racing conditions, the hub can flex so much that the pads get "knocked back" and the driver has to push the brake pedal twice before he gets full brake pressure - one push to get the pad back to the disc, another push to not smash into the wall
