now at the moment the little bit of erging I am doing is at 80df and I can assure you the fan does not wait for you to 'catch up' as on the recovery it does not slow down very much at all and you better haul arse at the beginning of the drive or your not going anywhere in a hurry. now of course I can slow the rate down and that means it (the fan) does have time to slow down that little bit more, or I can up the drag so that it 'does' slow down more, but heres the thing...
... if you are catching up to the fan easy at 20-22 spm and you think you have got it sussed and your feeling that 'catch' feeling the power come on, your going to have to be a dam sight faster at 34 to 'catch' it (the fan) in the same place on the drive, and give yourself the same drive length.
so what about it, train at a lower drag to develop 'fast' legs, so that when the rate goes up your not left behind
couple o' three of points:-
you can train at a lower drag then as you get closer to race time you can up it slowly so that you gain the benefit of the higher return
there is a temptation at lower drags to 'take the catch' with your arms as they are faster than you legs
low drag, shorter drive time, higher peak force reqd, seems to cost energy
cheers george