"ultimately, cranks, sprockets, and wheels are levers, and the final ratio, from the pedal to the road, is the only one that matters, at least on paper. In real life, rolling resistance is a factor. I am not very knowledgeable about wheel & tire sizes, widths, and resistance...I only know I love a nice 26" bicycle, I especially love mine after I extended the stays."
Augidog, when a human becomes the engine, I think other variables come into play. Just like the long rod, short rod argument, bicycle racers argue over long crank vs short crank. So, what do I think causes the argument? Probably confusion between spindle speed vs pedal speed. Even the best trained athlete has a sweet spot where they can perform at their best. In cycling, it is the maximum rpm one can maintain at the maximum watts produced for any given distance. So, rpm (cadence) is watched carefully. But what is happening out at the pedal? Using the grinding wheel example, a 20" wheel will travel farther and faster circumferentially than a 10" wheel. This is why grinding machine operators have to increase spindle rpm to maintain the same stock removal rate as the wheel wears. Now, if a longer crank forces the pedal to travel faster per revolution than a short one, does the rider have to generate more power to do it? Will this increase demand on the riders cardio? I maintain that it does, it almost has to.