Originally Posted by
The B
Not reduction- increase.
But you're right- my numbers are ********ly off. Obviously mixed up my CMs and my MMs in a spot or two.
But what I'd get is a 2.5mm INCREASE in saddle height, if I wanted it (not 25mm), and a 5mm overall decrease in pedal stroke diameter.
I think you get a decrease in saddle height (not that I think 2.5mm decrease/increase would be noticeable) by using a longer crank. Your pedal would be 2.5mm lower at the bottom of the stroke than where it is now so you would need to lower the seat, granted it is also 2.5mm higher at the top of the stroke. I don't know of anyone who sets their seat based off of where the pedal is at the top of the rotation though.
EDIT: My bad, I need to learn to read, yes a shorter crank would theoretically need a seat raise.