My view is that your formulas for calculating wheel speed are leaving something out. I can't tell you what that is -- just like I can't tell you why weather forecasts are so often wrong -- but my personal observations based on thousands of rides suggest that something is missing from your calculations. On paper, it may be a "proven fact" that wheel/tire weight has little or no effect on average speeds. In practice, many cyclists have observed that their speeds are slower when riding bikes with heavier tires/wheels.

Jan Heine, of the big proponents of fat tires, has conducted a bunch of tests on various tires -- concluding that fatter tires are faster than narrow ones. Curiously, his test involves measuring how far tires roll and how fast going downhill. Hmmm ... Do you think he would have gotten the same results if going uphill? Of course not, but you can't simply roll a bike uphill -- it has to be pedaled. I personally agree with his premise that wider tires are just as fast or faster than narrow ones -- if they are the same weight. However, wider tires are generally heavier than narrow ones, and that's why most cyclists perceive them to be slower.