Originally Posted by
n00bL35
Gads, if a 34/27 isn't cutting it you'd be faster carrying your bike up the hill. Are you hitting these hills with a loaded touring rig? You'd be hard pressed finding higher than 27 outside of MTB cassettes. Are you running 9spd Ultegra or 10? Otherwise, a triple chainring would give you a 30/27 arrangement, but you might need to swap out your right shifter and rear derailler to accomplish this.
A 34/27 at 80 rpm moves you at about 8 mph. I don't know about you, but I would probably not reach that speed running up a steep grade with a bike slung over my shoulder. Even if I did, I would not be able to maintain it for an hour. Besides, I would never feel like I conquered the hill if I had to get off and walk.
Davida, IRD makes cassettes with 32 and 34 cogs, but at about $150 it might be better to just switch to a triple up front.