Originally Posted by
Sardines
There is another issue you haven't touched, the gearing change from the circumference of the smaller tire. He'd be essentially running about 5-8% slower because of the smaller tire for the same effort. Pickup will be faster but once up to speed, the rider has to pedal faster for the same speed, negating the rolling resistance and aero benefits of a smaller tire.
Darn it! If only there was a way to change the gear ratios on a bike while riding...