How to Replace Derailleur & Brake Cables

The brake and derailleur cables on your bike control the brake calipers and derailleurs respectively. This allows you to stop and start the bike effectively by switching gears and activating he brake calipers to slow the bike down. Brake and derailleur cables are usually made of steel, and therefore over time they will rust and begin to stick the the housing that runs over them. Learn how to replace your brake and derailleur cables and keep your bike braking and shifting smoothly.

Things You'll Need

  • Cable cutters
  • Needle nose pliers
  • 5mm hex wrench
  • 2 new brake cables
  • 2 new derailleur cables
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Instructions

    • 1

      Loosen the brake cable stop, where the cable is clamped to the brake, on both the front and rear brake using a 5mm hex wrench. Cut the end of the cable using a set of cable cutters and pull the cable out of the brake cable stop. Remove the cable ends from the cable end mounts on both the right and left brake levers, then slide the cables out of the housing and set them aside.

    • 2

      Loosen the derailleur cable stop, where the cable is clamped to the derailleur on both the front and rear derailleurs using a 5mm hex wrench. Cut the end of the cable and pull the cable out of the derailleur cable stop. Push the cable toward the right and left shifters on the handlebars. When the cables begin to poke out of the rear of the shifters, pull them away from the bike and set them aside.

    • 3

      Attach the end of one new brake cable to the cable end mount on the right brake lever. Slide the cabe through the brake cable housing until it reaches the rear brake. Pull the cable tight underneath the brake cable stop bolt using a pair of needle nose pliers, then tighten the cable stop bolt using a 5mm hex wrench. Repeat this process to route a new cable from the left brake lever to the front brake.

    • 4

      Press the black downshift lever on both shifters until the shifter is in the lowest gear available. Insert a new derailleur cable into the cable opening at the rear of the right shifter. Slide the cable through the cable housing all the way back to the rear derailleur. Pull the cable tight beneath the rear derailleur cable stop and tighten the stop using a 5mm hex wrench. Repeat this process to attach the front derailleur cable to the left shifter and front derailleur.

    • 5

      Snip the ends of the new cables so that only about 2 inches of cable stick out from the brake and derailleur cable stop bolts. Take your bike out for a test ride. Test out the brakes and shift through all the gears on the bike to be sure everything is functioning properly.