Last week I was removing the stock cog on my conversion's rear wheel and it somehow crossthreaded and ruined the threads. Fearing the worst, I took it into the LBS that sold it to me and they said worst case they'll give me a new wheel (Alex TA19 laced to whatever low-end flip-flop hub they keep around), and they're going to check in to warranty, as they agreed with me that that should never have happened given the cog and lockring were put on at the factory and checked by LBS and me. Makes me feel (a tiny bit) better about paying the higher prices there.