My rides avg. about 40 ft. vertical gain per mile. Lots of 300-400 ft. climbs.

My winter bike has a compact with a 12-25. Last summer, I put a 12-27 on my summer bike which has a standard crankset. Some of the hills we ride have stretches in excess of 20%. Many of the hills have stretches in excess of 15%.

I just got some Reynolds Assaults for my summer bike, and put a 12-25 cogset on them. I plan to use them for club competitions and try to avoid super steep or extended downhills.

...Lysdexic...