Do the rear sprocket bolts realy need to be replaced once they have been removed? If there grade 8 and threaded into a aluminum hub i wouldnt think they could stretch. I had been told to replace them by a dealer and an indy said it wasnt needed. I find it hard to beleive that they would need to be replaced. I have allready reused them a couple of times now and torque them to spec with out any issues.