I cannot get my campy chorus 10 speed rear to shift right. As soon as I get one side right,the other side is a bit funny. I have 4600 miles on this set of cogs. Also, shifting is loud and rough. I replaced the chain at 3500 miles. Could this inability to adjust the shifting this time be due to cogs? Should I replace cogs and chain together? How many miles should I expect out of a campy 10 cog setup?