Thank GOD!! Someone posted about this issue, read up about KMC chains with Shimano drive trains. A lot of problems, I ALWAYS have problems with KMC chains. My problems are, the chain is louder, and worst of all is when I pound on the bike the chain will snap on the rear cogs and go down a cog set without me shifting. Its a problem with the chain because when I moved to sram or shimano chain, nothing but smooth riding and shifting. I advocate always riding sram or shimano chains for that reason. Its not like my issues happen with one drivetrain and 1 bike, its all my bikes that I've ever had. Also once my KMC chain snapped with about only 100 miles on the chain. Yep, KMC sucks.