One of my wheels has a SRAM casette on the back and works perfectly fine (all my bikes are variations of Shimano drive trains/shifters) - though I believe now that SRAM is marketing its own gruppos you would have to make sure you got the Shimano compatible casette. I believe that the cogs on the SRAM one are evenly spaced and the Shimano ones would not be, so it might cause shifting difficulties if you tried to mix and match.