Originally Posted by
dookie
i will be doing one this weekend on a well-supported local charity ride. 46/16 on an absurdly flat course (under 200ft vertical), comfy steel frame w/drops, bottle bosses & brake. i will be with a large group of capable riders and expect to average 20+mph.
That's flat and fast. Unless you can comfortably spin 90-100 RPM for 4-5 hours, I'd be tempted to go for 48/16 or 46/15.