What's the practical reason to have a compact crank? I know they weigh less, but what's the practical reality of the way the gearing affects one's ride and one's ability to find the right gear at the right time?
If I switch to a compact crank, would I need also to get a new freewheel with smaller/tighter gearing so I don't lose my top speed? I think my fastest gear right now is 52x14, so if I switch to a 50 or lower compact crank and a tighter freewheel (one that goes down to, say, 12), would the resulting 50x12 be faster than my 52x14? Even more dramatically, would a 48x11 be faster, or even comparable, to a 52x14?