Rolling Resistance

Rolling resistance is the force opposing a wheel's motion that arises from deformation rather than sliding. A pneumatic tire flattens at the contact patch and springs back thousands of times a minute; rubber and casing fabric return less energy than they absorb, and the difference leaves as heat. That lag is hysteresis, and it dominates the loss. The figure of merit is a coefficient, Crr, multiplied by the normal load.

Pressure has a breakpoint. Measured on a smooth steel drum, Crr falls steadily as pressure rises, which is where the folklore that harder is faster comes from. On real pavement the curve turns: past some pressure, further inflation stops absorbing surface texture and instead shakes the whole vehicle and rider, and that vibration is damped by suspension, luggage and body tissue rather than returned. Total losses rise. The drum figure is a measure that has drifted from the goal it stands for — see Goodhart's Law — and the road, not the laboratory fixture, is the Ground Truth.

The variables interact. A thin, finely woven casing bends with less internal friction than a thick one. Width helps too: at equal pressure a wider tire's contact patch is shorter and broader, so the casing bends through a smaller angle. System mass and surface roughness set where the breakpoint falls. Change one variable and the optimum for the others moves.

So "higher pressure is faster" is an Exhaustive Claim the data does not support, and the intuition behind it is a Plausible Mechanism describing only the smooth-surface half of the curve. Aerodynamic drag still dominates the power budget at speed, as a rough Fermi Estimation shows.