my buddies Power tap read about 60 watts more on flat ground than mine...we are the same weight and were doing the same speed.

we did intervals today and he was consistently +/-60 watts higher. the only difference was he was on bontrager x-lites and i was on Zipp 303's...they aren't that freaking aero that much i know.

what gives..

ps..i am new to the Powertap thing.