I'm pretty sure that its not because the chain is too short. I can see and hear it rub against the cage. When i loosen the pulleys screw 1/4 of a turn, the noise of it rubbing goes down. Only thing is that i dont know if it's safe to loosen the screw. I figure that if i put a spacer it will help. What do you think about putting a spacer in to widen the cage?