i've gotta agree with guitarwizard on this one. i have a 12-27 and wish i had an 11 on it. i don't need the 27 when i'm doing long climbs in socal, but when i'm doing repeats up that same climb, i'll drop into the 27 and noodle along during my recovery period. and i'm always spinning out the 12 on the descent. i should be better at fast spinning, but i'm not. i'm a masher, and an 11 would make the descent better. i could still get some effort into it