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Righty tighty, lefty loosy - most of the time.

May 13th, 2007 by Brad Quartuccio

Most are familiar with the old righty tighty, lefty loosey saying. It holds true for most everything on a bicycle as well - turn bolts right (clockwise) to tighten them, left (counterclockwise) to loosen them.

But there are two important places where this rule is different, and tends to confuse people.

The left hand side pedal (non-driveside) and right hand side bottom bracket cup (driveside) have left hand threads. This means you turn them to the left (counterclockwise) to tighten, and to the right (clockwise) to loosen. This is done to prevent either part from backing out due to riding, and is reasonably easy to remember. And even easier to forget. Next time you can’t get a pedal or bottom bracket cup to unscrew, take a step back and trace out the direction it needs to rotate in your mind before pulling out the really big wrench.


4 Responses to “Righty tighty, lefty loosy - most of the time.”

  1. 1 S. cerevisiae 

    I realize that the left hand threads are pretty uniform in cycling wrenching. What might help though is codifying them a la the rest of the mechanical world. There exists a standard observed by many in the automotive and industrial worlds wherein left hand threads are “signaled” by notches cut or cast into the heads of bolts or nuts. These littles notches have spared many from stripping out the threads in propane tanks and cylinders (P.O.L. fittings), and older Mopar driver side wheel lugs, for example.

  2. 2 Screw Loose 

    Flat as a board and screws easy!

  1. 1 dirtpedaler.com » Lefty Loosey
  2. 2 Blue Collar Mountain Biking » Blog Archive » Finger-Wrap-Rule (FWR) for remembering pedal threading. | Mountain Bike Reviews, Deals and How Tos

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