“Tires with a smaller diameter have a higher rolling resistance with the same inflation pressure, because tire deformation is proportionally greater. The tire is flattened more and is “less round”.”
Thanks to the German company wehave this explanation. Ein hoch auf uns!
This only means that smaller diameter tires need higher inflation pressure for the equivalent rolling resistance (or rather, deformation). That only becomes a problem when you approach the limits of the material (eg. you can't inflate it any more).
i don't know what he meant by it, but large wheels are better "flywheels" and that storage of momentum might make sustained pedaling easier.