I've noticed that there's an S10 version of the Gossamer compact that supports Shimano 10 speed. Does anyone know if the only difference between that and the original is the chainrings? And would it not be recommended for a 9 speed Shimano?

Thanks

In general I believe 10spd cranks work with 9spd draintrains and visa versa. There are differences in the spacing but it's relatively insignificant. I run 10spd Ultegra crank on a 9spd draintrain and it works great; shifting is flawless.

I am pretty sure all of the gossamer, SLK and k-force chainrings are intended for use with either 9 or 10... it wouldn't make sense to manufature two different widths of chainring teeth to accomodate a tiny fraction of a millimetre difference between 9 and 10 speed shimano chains.

As another example if you look at separate Stronglight chainrings in various sizes, 110 or 130mm BCD, they all say "9/10" printed on the side.

I run a Gossamer Mega Exo Compact with my Ultegra 10-speed setup. No problems. As far as I know, when I bought the gossamer they only made one type.

9 speed FSA did have some problems early on with 10 speed but that is no longer the case...your good!