My Atomic BB has a MM hub adapter, 40t alloy sprocket, and KMC 415 chain, that I bought from Pirate cycle a couple years ago. It has about two thousand miles on it. The teeth on the sprocket are in, not good condition, great frickin condition. The chain itself has streached out over the years, and I removed one more link last year. The chain is probably more worn out than the sprocket. I maintenance the chain often, and I always use a good brand of chain lube.