It’ll be easier to slide the old cable out of its housing if you snip off the crimped end. Otherwise, it’ll might get caught inside of the housing. Your new cable should come with a new end crimp. If it doesn’t, cable end crimps are inexpensive and available at bike shops.
The brake cable’s housing might have ferrules or end caps that secure it to the frame, lever, or retention clamp. Be sure to safely store these and any small parts to avoid losing them.
For a straight-handled bike, the brake cable runs through the adjuster, and a nipple at the end of the cable slides into the brake lever. In a road bike with curved handlebars, the cable threads directly into a clamp within the lever, so skip this step if you don’t have an adjuster. [4] X Research source
For curved handlebars, pull the brake lever, then find where the cable threads into a clamp within the lever mechanism. For some models, you can just pull the cable out of the clamp when the lever is engaged. [5] X Research source For other models, you might need to engage the lever several times to detach or attach the cable, or you might have to remove a cable cover to access the clamp. Consult a bike repair manual or search online for your bike model’s specific method.
You might not need to replace the housing if it’s in good shape. However, you’ll definitely need to replace it if it’s worn, stiff, rusty, packed with dirt, or has any kinks. For rear wheel brakes, a section of housing runs from the handlebars, and another runs from the wheel. The section that runs from the wheel gets dirty more easily, and you might only need to replace this section. [7] X Research source It’s wise to take pictures of how the cable housing is threaded around your bike’s frame before removing it. That way, you’ll have a reference just in case you forget. [8] X Research source For a road bike with curved handlebars, you might need to take off the grip tape to remove the cable housing. Peel off the tape, if necessary, then re-tape the handlebars when you attach the new housing. [9] X Research source
If there are 2 sections of cable housing, try snipping the exposed inner cable that runs between the sections. It’s easier to pull shorter lengths of cable through each section of housing than it is to slide out the enter cable.
To ensure that you get the correct replacement, take the old cable to a bike shop and ask an employee there to help you find a match. If you’re replacing the cable housing, be sure that the housing is labelled for brakes. Shift cable housing isn’t as strong and could buckle. [12] X Research source
Use caution when using wire cutters or any other sharp tools. If your bike has rear wheel brakes and 2 sections of housing, cut your new housing to match both sections. After cutting the new cable housing, inspect the cut ends. If the cuts aren’t clean and square, remove any rough edges with a metal nail file. [14] X Research source
If there are any ferrules, don’t slide them into the lever, adjuster, or retention clamp yet. You still need to slide the inner cable through the housing. The brake cable will not work properly if the housing bends sharply. Ensure any spots where the housing curves around the handlebars and down the frame are smooth and gentle. If necessary, secure the housing to the frame with small zip ties. After pulling them tightly, cut the excess lengths off of the zip ties for a cleaner look. [16] X Research source
The end of the cable that slides into the retention clamp at the brake mechanism should be just plain, bare wire. If an end of the cable has a nipple, make sure it’s positioned near the handlebars. For a bike with a rear wheel brake, slide the remaining length of the cable through the second section after threading the first. Before threading the second section, you can slide rubber donuts over the inner cable. They’re available online and at bike shops, and will prevent the exposed metal cable from rubbing against the frame and messing up your paint job. [18] X Research source
For drop handlebars, engage the brake lever, find the clamp or eyelet inside, then thread the end of the cable through the mechanism. [20] X Research source Check the manufacturer’s instructions for your model’s specific threading method and, if necessary, replace the cable cover.
While optional, a fourth hand tool makes it easier to tighten the bolt. Grasp the end of the cable with the tool’s opening, then squeeze the handles to tighten the cable as you turn the pinch bolt clockwise with the Allen wrench. [22] X Research source
If you don’t have a repair manual handy, find your bike’s model number and search for the manual online. Most manufacturers publish instruction manuals on their websites. If you removed the grip tape from drop handlebars, re-tape them. Tape over the new cable and housing so they’re in the same position as the old set. Purchase new grip tape online or at your local bike shop.
If the lever is too tight, loosen the barrel adjuster at the lever or unfasten the pinch bolt to give the cable more slack. If the lever feels loose, tighten the barrel adjuster. If it’s still too loose, unfasten the pinch bolt, pull the cable tighter with a pair of needle nose pliers or the fourth hand tool, then tighten the pinch bolt. For the most accurate method of adjusting the tension, use a fourth hand tool and torque wrench to tighten the cable to 6 Nm or to the manufacturer’s specifications.
Some bike mechanics recommend leaving about 3 inches (7. 6 cm) of cable exposed from the brake clamp so there’s enough length for future adjustments. However, there’s a risk that this length could get caught in the wheel or brake mechanism. If you choose to keep the end long, hook the extra cable securely around the brake, and be sure it doesn’t obstruct the wheel or brake pads. Alternatively, just trim the excess wire to about 3⁄4 inch (1. 9 cm).
If you have trouble, ensure the cable’s connections to the lever and retention anchor are stable. Double check that engaging the lever causes the brake pads to close around the wheel. If you can’t find the problem, consult a bike mechanic.
