If I recall the wind tunnel tests it seems that air drag becomes the main factor besides rolling resistance at speeds above 16MPH. At 30 MPH about 90% of your energy is going into defeating wind resistance. If you can get down into a racing tuck you will notice a big change in performance, at least I did on my old road bike. Unfortunately most people cannot ride ina full racing tuck for hours on end without discomfort. my new bike, although a good deal heavier than my road bike offers a riding position that provides low wind resistance, about the same as a rider on a road bike in a full racing tuck. I do have full visibility and nothing gets sore over extended rides. The heavier bike is slower to accelerate but still climbs well. On the flats it is as fast or faster than the road bike, and down hill it screams.

If you have the need for speed run high pressure tires fully inflated, set up the right gearing, and adjust your bike so you can pedal efficiently while maintaining a low aerodynamic profile.

'bent Brian