This is another awesome post, although it doesn't address the one thing about bicycles I can never remember - which of the pedals has a reverse-threaded attachment to the pedal crank arm, and what's the complete force-based explanation for this necessity?
I'm not even sure if the force responsible for this is friction-related, or torque related, or some combination of both (probably the latter). The force is transmitted to the chaindrive in an off-axis manner, but the pedal itself is further removed from the axis, so when you push down on the pedal axis that's ahead of the bottom bracket axis - one side will tighten clockwise from the pedal's perspective, and the other side will tighten anti-clockwise.
Wow I got it right after going through this post! That's a first, though I'm still not sure I got all the forces right.
I'm not even sure if the force responsible for this is friction-related, or torque related, or some combination of both (probably the latter). The force is transmitted to the chaindrive in an off-axis manner, but the pedal itself is further removed from the axis, so when you push down on the pedal axis that's ahead of the bottom bracket axis - one side will tighten clockwise from the pedal's perspective, and the other side will tighten anti-clockwise.
Wow I got it right after going through this post! That's a first, though I'm still not sure I got all the forces right.