another question boo : ( i exchanged the wheels for mavic cxp22s had the lbs change the lockring and now the cog seems to make some noise i went back and asked them to take a look at it they took it off and reput it on and it still makes the noise could it be the chain? maybe dirty? i've been messing around with the tension on the chain and it seems how no matter how i move it it still makes the noise. should i just live with it? it's not loud or anything but i can hear it when i'm riding.

Any advice?

It sounds like this video
http://www.youtube.com/watch?v=e5UfCsTKbQY