Oh and just to demonstrate that wide tires are not necessarily slow, the fastest North American finisher in PBP 2007 covered the 1200k (750mi) in 50 hours flat. On a 30+ year-old steel bike. With 700x30c tires, metal fenders, a canvas handlebar bag and dynohub lighting. Does anyone honestly think the bike was holding him back? He (Jan Heine) doesn't.
(And before anyone states the obvious, yes, I know the motor makes a HUGE difference. I'm just sayin' that "whatever the pros are using this week" isn't always the best choice.)
SP
Bend, OR