10sp cranks on a 9sp?
 

I have an opportunity to get a set of FSA compact cranks on the cheap, but they came off a bike with 10sp Shimano and all my stuff is 9sp Shimano. Assuming 10sp chain and chainwheels are slightly narrower, wouldn't the crank and chainwheels still work with the 9sp chain and cassette?

Still getting up to speed (arrgh, arrgh) on the newer bike tech.

SGS

Isn't a problem. The chainwheel on the 10spd is slightly narrower is all. In fact a 9 spd chainwheel will probably work just fine with a 10spd chain. The cassette is the issue not the crank on 10 spd/9/8/7/6/5 spd questions.