What 55/Rad says about the 20+ pace over long distances being possible for mere mortals is totally true. I did Ride Across INdiana (RAIN) last year, my first year of road riding (although I had commuted for a decade). I had ridden about 1000 miles total on the roadie, and only two centuries, ever. Decided on Wednesday to do the ride on that upcoming Saturday, on a whim. Despite riding 2 hours of it alone at 15-18mph (because I am a rookie and an idiot), I still averaged 19.7mph over the whole 164 miles. You find a good wheel to suck on and just sit back and enjoy the ride! Can't imagine what the pace would have been if there'd been any tail wind that day....