Timcupery,
Thanks for the input. Yes, the cassette hub does need a shim. I just want to know why the shim should be on the inside when the chain alignment seems(open to interpretation) better with the shim on the outside. The hub is a Mavic 10 I believe. I bought a cheap set of new Cosmos for training/weather wheels. I have an older set of SSC's that have the nine hub and no need for the shim. This is all new to me so sorry for the confusion on this end of the keyboard.