I'm not a physicist, and I didn't stay at a Holiday Inn Express last night, but a lot of our MTB customers actually run a fatter front tire (larger footprint=better cornering grip), and a narrower rear (less weight). This runs counter to what people are accustomed to seeing on motorcycles, but then most people can't lay down the horsepower that a motorcycle can. I'm not sure if that same principle works on road bikes..... I'll have to do some asking around with the engineers. I'm guessing that on a road bike, there is some wind resistance penalty for having a fatter tire cutting the wind. The rear tire slipstreams behind the seat tube, so I wouldn't expect wind resistance to be as much a factor.