Originally Posted by RTDub

This is a question best posed in the Mechanics forum, or better yet, a search in the Mechanics forum.

Needless to say, when you use 9 speed stuff with 10 speed stuff, you are asking for incompatibility. I learned the hard way with a 10 speed 105 crankset with 9 speed everything else. Front derailleurs matter, chain matters, and if you get a 10 speed chain for your crank, your 9 speed cassette may have a little bit of difficulty shifting, but nothing tragic. A 9 speed chain with a 10 speed crank will invite rubbing as the rings are spaced a little differently, and 10 speed chains are narrower to match.

But do go consult the Mechanics forum. Better answers over there.