How to Remove an External Bottom Bracket Crank

Bicycles employ a "crank" device to rotate the drive train and propel the bicycle forward. The crank is attached on the bicycle to a part called a "bottom bracket." External bottom brackets have a pair of bearing cups that are positioned on the outside of the bottom bracket shell -- the cylinder-shaped tube at the bottom of the bicycle. A spindle passing through the center of the bottom bracket attaches both sides of the crank, allowing them to turn in unison during pedaling. Learn to safely remove your crank for replacement or servicing of its individual parts.

Things You'll Need

  • Shimano TL-FC16 tool
  • 5 mm hex key
  • 8 mm hex key
  • Campagnolo UT-BB110 tool
  • Flat blade screwdriver
  • 17 mm open wrench
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Instructions

  1. Shimano

    • 1

      Place yourself before the left-side crank. The left side of the bicycle is the side opposite the chain.

    • 2

      Use a 5 mm hex key and loosen the pinch bolt at the end of the crank opposite the pedal. If there are two such bolts, loosen both. Removal of these bolts isn't necessary.

    • 3

      Insert the splines on the side of the Shimano TL-FC16 tool into the bolt at the center of the crank.

    • 4

      Turn the TL-FC16 tool counterclockwise and loosen the bolt. Remove the bolt.

    • 5

      Pull the left side crank arm to separate it from the bottom bracket. Then pull the right side crank arm to also separate it from the bottom bracket.

    Campagnolo

    • 6

      Fit the narrow tip of the UT-BB110 tool into the bolt at the center of the right side crank arm. The right side is the same side as the chain.

    • 7

      Attach a 17 mm open wrench around the sides of the UT-BB110 tool.

    • 8

      Rotate the 17 mm wrench counterclockwise, and loosen the bolt. Remove the bolt from the side of the crank.

    • 9

      Note the retaining clip on the right-side external bottom bracket cup. Use a flat blade screwdriver to pry the clip free of the bottom bracket cup.

    • 10

      Pull the right side crank arm away from the bicycle. Then, pull the left side crank arm away from the bicycle.

    Sram

    • 11

      Look for a bolt at the center of the left- or right-side crank arm. Place yourself before this particular crank arm.

    • 12

      Fit an 8 mm hex key into the bolt at the center of the crank arm.

    • 13

      Turn the hex key counterclockwise, and loosen the bolt. Remove the bolt.

    • 14

      Pull the crank arm away from the bicycle. Then pull the opposite crank arm away from the bicycle.