Replacing brake cables

Brake cables are a critical component of your braking system. You can have new brake pads, but if your brake cables give out, you won’t be able to stop your bike when you need to. Each time you give a hard squeeze to your brake levers, the cables must transfer that force to the brake pads. Over time, this force will wear out the cables, causing them to kink, fray, or bend. If you see these signs of wear with your brake cables, do the safe thing and change them immediately. Here’s how:

1. Unfasten the brake cable by loosening the nut or bolt where the cable attaches to the brake arm.

2. Squeeze the brake lever so that the nipple at the end of the cable is showing.

3. Grab the end of the cable with a pair of pliers and pull the cable slightly out from the brake lever.

Before you remove the brake cable, take a moment to observe how it is routed around the frame of the bike. Pay attention to the location of the cable housing and where the cable housing meets the cable stops and the cable exits on the other side. You’ll need to route the cable and cable housing in the same manner when you reinstall it. You want the housing to be as short as possible. The housing should have gradual curves with out any binding or sharp angles.

4. Once you grab the cable, use your hands to remove the entire length of the cable (see Figure 8-20).

5. Collect any ferrules that were holding the cable housing in place at the anchor points.

You’ll use these when you reinstall the cable.

It’s a good practice to change the cable housing when you replace cable wires. Manufacturers often sell cable with the housing included in the package. They normally give you more housing than you need so you’ll have to cut it to fit your bike.

Figure 8-20: Removing the cable.

6. Cut the cable housing with cable cutters (see Figure 8-21).

Cable cutters are useful because they cut the housing without compress­ing the end too much. Assuming the old housing was the proper length, use the older pieces of cable housing as guides for cutting the new pieces.

Even if you use a cable cutter, you may need to file the end of the cable if it has any sharp edges. You may also need to open the end of the housing up with an awl or other pointed instrument if the end looks like the example on the left in Figure 8-22.

7. When you’re ready to install the new cable, use a rag to apply a light coating of grease to its surface.

8. Squeeze the brake lever and insert the cable into the hold from where you originally removed it (as shown in Figure 8-23).

You may have to wiggle it around to pass it through the brake lever. Pull the cable out the other side of the brake lever.

Be cautious with the cable tip to prevent it fraying during the installation.

9. Attach the ferrules that came with the cable housing to the ends of each piece of housing (as shown in Figure 8-24).

10. Insert the cable into the proper cable housing and pull it out the other end.

Figure 8-21: Cutting the cable housing.

Figure 8-22: Properly cut cable housing.

Figure 8-23: Inserting the cable.

11. Route the cable and cable housing around the frame of the bike in the same position as it was previously.

The ferrules at the end of the cable housing should fit snugly into the cable stops on the frame. In some cases, the ferrule will not fit in, so just remove it — the cable stop acts as built in ferrule at this location.

12. While holding the brakes against the rim with one hand or a fourth — hand tool, tighten the cable anchor bolt.

13. Test the brakes by squeezing the brake lever as hard as you can three or four times.

Figure 8-24: A ferrule.

A brake cable may break on you at some point. If this happens, you can continue to ride, although you’ll need to use more caution and give yourself greater stopping distance. The front brakes have much more braking power than the rear, so if you’re lucky, your rear brakes will go out. This is why you have to replace your front brake pads more often than the rear. Just be careful that you don’t apply them too quickly; otherwise, when your front wheel stops, the momentum from your body might send you flying over your handlebars. If the front brake cable breaks on a long trip, replace it with the rear brake cable.

This will stretch the brake cable and seat the ferrules. You may need to readjust the brake cable after this.