One of the pads on my rear Juicy 7 is intermittently lightly rubbing the rotor (Causing a moaning sound), HOWEVER... When I stop and spin the back wheel and watch it, the pads appear to be centred, and there's no visible contact. One of the ways I can get it to make the noise is by swerving the bike back and forth as I'm riding. Might this be loose wheel bearings, allowing the rotor to move back and forth, or what? Thanks!