maybe its just me, but, I was muchmore effecient on my new bike today with the 700c's. Yes, there was less wind, but I am sure I was more effecient maybe the bike is just better. My new bke is a novara carema pro with 105 everything. The old bike with 650c's is a 2003 trek 2200 WSD. Don't know, what's up, but I love my new bike.