Originally Posted by
63rickert
Did anyone here ever do this?
Pedal stroke is different with the shorter crank. That's the whole idea.
In practice, adopting cranks 10mm or 20mm shorter means putting the saddle up 2 to 5mm. For a change in crank length of 5mm or 10mm very possible no one bothers.
Some of us have actually done this rather than spinning tales about theories.
The other one that theorizers always use is shorter cranks mandate lower gears. No, does not happen. The old gears work just fine. Maybe better, as the power stroke is better.
When I went to a shorter crank, I kept my seat height the same because I was looking to both reduce the amount of extension at the bottom as well as limit the knee bend angle at the top of the stroke. This was to resolve some IT band issues. I figure the need to adjust depends on one's goal.