Hi Bess, tried moving the sprocket round all positions have the same problem, tried a few different things then tried leaving out the outer sleeve and it tightened up ok, I think the sprocket side bearing may be the problem it measures approximately 16 mm wide whereas the brake side measures 14mm , off to c&d in the morning to check the sizes, I suppose I could always cut a couple of mil of the sleeve if necessary, cheers, Dave.