Bike Maintenance: How to Replace a 2-Piece Crankset

If you want to clean your frame or work on your chainrings, or if one of your crank arms needs to be replaced, you’ll need to remove the crankset. In this video, we show you how to remove the left crank arm, remove the crankset, replace the crankset and tighten the crank arm. Shop REI’s selection of bike cranksets at http://www.rei.com/c/bike-cranksets.

Video Transcript
Being able to remove your two piece crank set is handy if you want to clean off your frame, work on your chain rings, or if one of your crank arms needs to be replaced. You'll need a number 5 hex key, a torque wrench, and a bottom bracket tool. First, lift the chain off the chain ring, and rest it gently on the bearing cap. You can push the tensioning arm forward to loosen the chain. Then, loosen the pinch bolts on the non-drive-side crank arm, but don't fully remove them. Now, you can use the bottom bracket tool to remove the plastic preload cap, and set the cap aside. With the cap off, pull the left crank off the spindle. Then, tap the spindle loose with your
hand. If it needs some encouragement, gently use a rubber mallet.

Once the spindle is loose, pull the crank and chain rings out the other side. When you're done with your work, and it's time to replace the crank, slide the spindle through the bottom bracket shell, and tap it into place with the heel of your hand. Replace the left crank arm, followed by the plastic preload cap. Gently tighten the cap with your bottom bracket tool. Next, tighten the pinch bolts on the crank arm, but don't fully tighten one bolt before the other. Go back and forth on each bolt until they're hand tight, then use your torque wrench to reach the specified torque. Finish by moving the chain back onto the chain ring, and shifting through the gears.

To recap, loosen the pinch bolts. Remove the preload cap, and pull off the left crank arm. Pull the crank and spindle through the bottom bracket shell. Replace the crank and spindle, and reinstall the left crank arm, and preload cap, and tighten the pinch bolts.