been hearing a banging or rattling noise on the back end of my bike when i hit bumps . was just looking it over when i crabbed the disc for the rear brake and noticed it was loose. its not wear the disc bolts to the hub its above that wear there is a bunch of holes that look like washers all around the disc these are all lose . you can crab the disc and move it very easily. the front brakes are all tight so I'm am guessing this is not right. any one who nose more about this then me you help would be great!!