How to Install Front Derailleurs

Bad things can happen to good parts. All parts on a bicycle are important, but a rider who loses the ability to shift between the rings on the front crank is generally in for a miserable ride. The front derailleur handles this task and is therefore vital for providing the full range of available gears. So, occasionally a rider will have to install a front derailleur. With only a couple of tools, this task is relatively elementary.

Things You'll Need

  • 5mm Allen (hex) wrench
  • Dime
  • Pliers
  • Cable cutters
  • Cable end cap
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Instructions

    • 1

      Attach the derailleur to the bicycle using the 5mm Allen wrench. Depending on the type of derailleur, it will either bolt directly onto the mounting tab -- also known as a boss -- already attached to the frame or by wrapping the clamp around the seat tube and tightening the bolt. Tighten just enough so that it can be moved, but does not slip.

    • 2

      Position the derailleur so that the edge of the outer cage is 1 or 2 mm above the large chain ring. Use the dime to check the clearance.

    • 3

      Align the outer cage of the derailleur so that it is parallel to the large chain ring when looking directly down on it from above. Gently rotate the derailleur until you achieve the proper alignment.

    • 4

      Fully tighten the derailleur mounting bolt using the 5mm wrench.

    • 5

      Shift the left shifter lever so that it is in the lowest gear to make the most cable available for attachment to the derailleur. This generally involves pushing the inner lever on STI shifters.

    • 6

      Attach the cable to the front derailleur by threading it behind the anchor bolt on the upper part of the derailleur and pulling and holding it tight with the pliers. Tighten the anchor bolt with the Allen wrench.

    • 7

      Cut the cable about an inch past the bolt using the cable cutters.

    • 8

      Place the end cap on the cable to prevent fraying. Very gently crimp the cap with the cable cutters.