Has anyone ever determined the best way to drop weight fast with the bike being the main form of exercise? I keep hearing about how any road bike over 20 pounds is supposed to be some sort of tank or something...and it got me thinking. Is it better for the bike to be heavier = more effort to push forward and burn calories? or a super light bike to allow for faster, sustained spinning? Is a flat bar with 105s the best of both worlds for strictly weight-loss riding? Or maybe something heavier like a steel jamis quest? Anyone figure that out yet?