Pete's Tech Trivia

Here's a quick brain-teaser for those of you who wrench on bikes: 

Ever wonder why the threads on pedals are "handed" (right-hand thread on right, left-hand thread on left)? And those English-threaded bottom brackets, the same thing.. the threads on each side go in opposite directions? It doesn't make sense if you think about a pedal bearing locking up, because it's not hard to envision the pedal "unscrewing" from the crank. Same with the bottom brackets.

What's up with that?   

Answer: "Precession". Precession is a not-so-intuitive phenomenon that assures that a properly functioning pedal will stay tight on the crank, and same for bottom brackets. If you've been around more than a few decades, some of you may remember when lug nuts were also "handed", left and right. Google it! Gives you something to talk about on those long country group rides. 



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