Originally Posted by
Abe_Froman
I'm afraid I'm not going to be able to explain it particularly well....but there's a Sheldon Brown article on it somewhere.
Here ya go!
https://www.sheldonbrown.com/brandt/left.html
https://en.wikipedia.org/wiki/Precession_(mechanical)
Clif Notes version: "It's Complicated!"
BTW, the left-handed threads on the NDS pedal are generally attributed to the Wright brothers! (
https://en.wikipedia.org/wiki/Wright_Cycle_Company)
Steve