I'm not mechanically inclined at all so I may not even explain this right.

In an effort to improve my low gearing, I've been looking at going to a compact gearing system. Right now my front gears are 53/39 and the rear is 12/27. I'm looking to change the front to 50/34 which I think will be sufficient. Maybe someday I'd look into making the rear a 10-speed 11/27 if they ever offer it.

Anyway, I'm getting conflicting info. I have a dura-ace front derailer and an FSA carbon crank. So far everyone seems to say the front derailer is fine, even if I change later to a 10-speed too.

But one source says I merely need to change the rings to the ones I want while another says the compact setup has something (bolt holes maybe) at a different spacing and thus you MUST change the crank too which means lots more money.

Then the first guy tells me that is true only if you go with the compact setup, but I gather from him that it isn't the 50/34 that makes it "compact". I thought it was, so what's the deal here?

Can I switch to a 50/34 without changing to a compact crank too?

What makes it "compact"?

If it isn't the rings that make it compact, what is the advantage of a compact set-up compared to one with the same front rings that isn't compact?