How to Install Bike Cables

Loosen the bolt holding the cable at the component end (i.e., the derailleur or brake). Most bike components use hex bolts, with derailleurs and brakes typically using 5 to 6 mm wrenches. Turn the bolts counterclockwise (left) to loosen. When the bolt has been loosened, pull the end of the cable out from behind it.

Trace the cable to the other end of the component. For example, if you've taken the cable off of a brake, trace the cable back to the brake lever. Take note along the way of the path the cable takes, and any cable guides that it may go through or over. Find the end of the cable---it will have a small metal knob on it. If the cable is on a brake lever or handlebar shifter, the end is often covered by the housing of the brake levers. Shift those out of the way with your fingers, grasp the cable end, and pull the cable all the way out.

Prepare your new cable by unwinding it from its packaging and putting a couple of drops of silicone lubricant on the bare end. Insert the bare end through the opening you pulled the old cable out of and firmly push it through the cable housing. When the cable appears out of the cable housing, route the cable to the component you'll be attaching it to, following the path you observed in Step 2.

When the end of the cable reaches its destination, slide it underneath or through the bolt that holds it in place, and pull it until all the slack is out of the cable. Tighten the bolt holding the cable and adjust the tension of the brake or derailleur.

When the component is operating properly, cut off any excess cable, leaving 1 to 2 inches extra. Slip a ferule over the end of the cable (it comes with the cable) and crimp it into place with a wire crimper.