my post doesn't assume that when pedaling a bike on a stand people are always exerting a force. many times i've seen them just chasing the freewheel with the crank and changing gears at the same time. in fact, IME, it constitutes the majority of the time when testing a RD on a stand. mostly, i suspect, it's because it is so easy to spin out the wheel when there is no load on it. one only has to overcome the inertia of the wheel and in order to maintain the speed, the drag of the bearings and the minor air resistance.

this has made me wonder, if anybody that did or does RD tuning a lot, like a mech, for instance, if they have had reason to create some sort of artificial resistance device to more accurately mimic real road conditions and forces.