Originally Posted by
bruce19
Only if crank arm length remains the same.
Maybe I'm not clear on what we are talking about. You can set and adjust saddle height on a given bike based on measuring from any fixed point on that bike. As long as you do the numbers consistently, it will work. If the crank is changed, one needs to think about how to compensate so your leg extension remains the same.
But I don't see how it can be true that measuring from the BB axis to the saddle top is the only valid way to address saddle height.