have you checked to see if you have any side to side move ment on the rear wheel?.with the bike off the stand see if you can feel movement by rocking wheel side to side,everything should feel tight.if one of the bearings has collapsed you will be able to feel a lot of free play .the bearing that gets the most hammer is on the drive side ,also do not rule out a seized bearing ,check this with bike on stand and see if you can spin wheel freely .if all appears ok then remove drive cover and inspect the belt.you could also try reving bike on stand to see if you still get the noises you describe ,if it only does it when engine is under load ie when you are riding,then it will most likely be the clutch rollers,only about 8 quid but I little bit of a pain to fit .hope my input helps m8 and good luck.
mech monster, October 2011
