i was pretty much expanding on the concept brought up in the first paragraph of the second response in the thread. and why it happens on the road and not on the stand.

as an experiment, i just tried it on my geared bike. what i did, and what most people do, i think, when testing a DR is to spin up the rear wheel and then test the shifting while the freewheel is, well, freewheeling. the freewheel is turning sure enough, but not as fast as the wheel.

and the chain sags both above and below the chainstay while shifting. if anybody is interested try it.