Today I learned that the left bike pedal is reverse-threaded—tightened counterclockwise and loosened clockwise—and it’s not just a random design choice.

It’s intentionally designed this way to prevent the pedal from unscrewing itself while riding, thanks to a physics phenomenon called precession. Pretty cool how engineering accounts for even the tiniest details!

Here’s a simple mnemonic by Lex to keep this in mind:

“Left pedal - ’left’ threading, not ‘right’!”