Change a Crank

If you are ever your riding your bike and find you need to change a crank, you have come to the right place! These instructions will teach you to change a cotter-less crank, not a cottered crank.

Steps

  1. Unscrew the bolt at the side of the crank arm with a socket wrench. Most often these are held in place with an 8mm hex bolt.
  2. From here, you may have to wiggle the crank or tap it with a hammer and work the crank off of the spindle of the bottom bracket. The best and easiest way to do this is to use a Park crank removal tool.
  3. When using a crank wrench (highly recommended): tighten the bolt into the spindle with a crescent wrench, before you insert the second part of the tool. This will keep the thread from stripping if you have to apply any kind of force to it to remove the crank.
  4. Clean the spindle mounting surfaces and put a small amount of lithium grease on the spindle to keep the metals from binding.
  5. Slide the new crank in.
  6. Tighten the bolt up, torque to manufacturer's specifications (approx 304-435 inch pounds from Shimano's website)
  7. Do the same for the drive train side, just don't forget to slip your chain off of the chain rings.



Tips

  • Use the right tools!
  • Wear old clothes.
  • Get someone to help.

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