Epic Fail today...chain jumped off the outer ring, locked up, hit the spokes and ripped the back end off !! Four bends in the chain and a 5 mile walk home after the chain couldn't run straight, and snapped a further two times . Not a happy biker today. Was surprised how brittle and weak the X-0 was under close inspection? The Deore on my other bike runs all day. I would never go X-0 again apart from gripshift as an option.