1977 Z650 - Have a clunk when I apply my rear brakes. WHen aplied lightly, the clunk is not there, but when moderately or more heavily applied, I get a clunk and an increase in braking. It also throws me on teh seat a little, so it's not a mild clunk. When this happens, the brake pedal has to be pushed further to get braking. The brakes are fine, work quite well apart from this issue. The torque link from the rear drum is solid, no movement there, and the swingarm bearings seem fine, no movement when rattled on the centre stand and no weird handling that I can tell. Could this be a brake shoe/actuator problem maybe? I'd like to sort thi out before I encounter wet roads! Regards, Andrew.