Originally Posted by
Machka
No, I don't think it would make that much of a difference. My mtn bike weighs 40 lbs, and my road bicycle weighs 27 lbs.
Not to judge but 2 km/h difference is negligible. Your road bike weight does seem a bit high, but the differences I get for a 30lb MTB and a 17lb road bike is closer to 10 km/h if not more. There's more drag based upon riding position and then tires make a huge difference too.