Originally Posted by
Carbonfiberboy
I measure with my legs, getting my knee bend right. I use the heel-on-pedal method to start with and then fine tune by feel. I get one bike right, then use the same method of measurement to transfer that to other bikes, usually measuring right up the seatpost.
This is pretty much how I have done it since some time in the early 80s except I don't try to replicate it on other bikes. This, that and the other thing I think are enough of a difference that I don't think that always works well. But heel on pedal or knee slightly bent on the down stroke is close enough that it isn't hard to dial in from there.