How to Fix a Bent Sprocket

Sprockets, also known as the cassette or gear cluster, are the toothed rings found on the right-center of a bicycle's rear wheel. When you shift gears, the chain moves up or down the sprocket to the ring set and calibrated for the gear. Bent sprockets cause disruptions in the shifting, and may cause the chain to come off the drive-train. For mild bends on a sprocket gear, use a mild method of straightening the metal. Severe bends require the bent sprocket be removed and replaced.

Things You'll Need

  • Degreaser and pan
  • Chain whip
  • Towel
  • Rubber mallet
  • Flat work bench
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Instructions

    • 1

      Wrap the chain whip, a specialized tool for removing the sprocket, around the largest sprocket on the gear cluster. Twist the handle so the cluster loosens on the hub.

    • 2

      Remove the sprockets and unstack them to get the bent sprocket. Pour degreaser into the pan and dip the sprocket into the fluid. Wipe it off to remove grime and grease.

    • 3

      Place the bent sprocket on a flat work bench so the bend is down on the flat surface. Place a towel flat over the sprocket.

    • 4

      Tap the bend gently several times using the rubber mallet. Be sure to keep the towel over the sprocket as you tap. Every few taps, take the towel off and inspect the sprocket to see if the bend is removed. Continue tapping until the sprocket is smooth and straight.

    • 5

      Reassemble the sprockets and put them back on the bicycle's hub. Use the chain whip to tighten by wrapping around the largest sprocket and turning clockwise.