williaty

The poster after you covered a lot of it, but I'll take a swing at it too.

Two things are true simultaneously:

1) Bigger diameter wheels have a larger circumference (they roll farther per revolution)
2) How far you roll per revolution has no meaningful impact on how much work you have to do to go a given distance.

Your effort is per unit distance not per revolution. So you're going to work the same amount to go a mile regardless of the size of your wheel (within reason. We're ignoring, say, roller skate wheels or wheels so big you need a ladder to climb on). The dominant factor in how much work you have to do is (for normal people speeds) whether you're going uphill or down. The second biggest factor at normal people speeds is going to be your overall efficiency which is composed of things like your chain path (tubes, idlers, etc), if your drivetrain is in good condition and lubed properly, losses in the tire/tube, wheel alignment, and other mechanical factors. The smallest effect at normal people speed is going to be aerodynamics (again, assuming we're ignoring things like carrying a 4' diameter pinwheel off the back of the trike). Wheel diameter doesn't play into any of that other than a very small impact on your mechanical losses due to slight changes in rotational speeds of the bearings in the hubs.

To say it a different way: You have to do the same amount of work to go the same distance on the same course in the same weather because the amount of work you do is based almost exclusively on things that don't change with wheel diameter. How far your travel each time your wheel turns over doesn't matter because the *distance* matters, not the wheel turning over. If you turn your wheel over 1.3 or 0.8 times per meter doesn't change the fact that you still had to ride a meter and *that's* what actually matters.


The meter maters. The revolutions don't.