Hey guys, Just want to get some opinions from you guys on what you think about this situation. I took my bike to get new tyres which was not too bad, there was a bit of a wait while they were ordered but fitting was free and i was in no big rush. When i got my bike back, after about 120kilometers of commuting i heard a slight rattle each time i accelerated from traffic lights at a normal speed, nothing excessive. I thought hmm somthing is loose never mind ill get it when i get home. Got to work, parked bike finished work get on bike, warm up, gear on, take off with some throttle and bang! the rear chain has slipped off... Now the chain and cogs were not brand new, they looked fine to me but now it is binding in certain areas and its making alot of noise. The mate that came to help me pointed out that the locking nut to the nut that holds tension on the chain is missing on both sides so the chain has come looser and looser (must have been that rattle!) and now so loose it has popped off under load. I don't know if there were ever any locking nuts on there i never noticed, should the bike shop have noticed and advised me / replaced these nuts in this situation? Now the bike is not usable until i get a new chain and cogs ($200 plus the time i take to fit it or $100 for the shop to fit it) Was the shop negligent in this case?