Maintain and replace brake and gear cables

Swapping cables is a simple job you can do at home. Here’s how…

Never mind fancy electronic shifting and disc brakes, back in the real world that most of us inhabit, mechanical gearing and caliper brakes are still the most common gear and brake systems around. They are also easier – and a fair bit cheaper – to service and replace and, if you look after your bike’s cables, these loyal ‘workhorses’ should give you years of safe and efficient service.

Cables do become worn and frayed with use (especially if you’re not too keen on cleaning your bike), and then it’s time to replace them. This job is well within the gift of the amateur home mechanic – you just need some basic tools (cable cutter, side cutter, file and pointer), a little patience, and a good supply of ferrules and end caps is very useful. Oh, and tea and biscuits always seems to help too.

01 Remove brake cable

Back off the cable adjusters, undo the inner cable at the caliper and cut off the cable end. Pull the brake lever and push the cable through the lever. Undo the top half of the bar tape, remove the brake outers and slide the new inner through the brake lever and out the housing bottom. It’s easier to undo the lever from the bar before threading the cable. Slide the first section of the outer over the inner and check the cable fits tightly.

02

Fit the new brake cable

Tape the outer cable to the bar. Fit the protective casing over the outer, tape in place then fit bar tape. Feed the rear brake’s outer cable to frame stops or through guides. Ensure any quick release is closed, thread inner through the cableclamp slot and fasten roughly in place. Turn the cable adjuster one turn anti-clockwise.

03

Cut the gear cable outer

Check the outer gear cable length. The rear piece should be long enough that the curve is not too tight. Use old outers as a cutting guide. Use sharp cable cutters to trim this gear outer. The end may flatten so squeeze it into shape, file to get it as flat as possible and open the liner with a sharp pointer before fitting ferrule.

04

Remove the gear cable

Select top gear. Back off adjustment on all cable adjusters – derailleurs, down-tube stop and shifters. With both derailleurs, loosen the cable clamp bolt and push the inner cable out through the shifter – pull the lever hood to one side if needed. Remove the outer cabling – you’ll have to undo the top section of bar tape.

05 Fit the new gear cable

Feed the new inner through the shifter lever, housing and first section of outer. Ensure the cable fits tight to the lever body and tape to the bar. Feed inners through the stops, bottom bracket guides and outer cable. Check the ferrules are seated. Feed inners through the correct side of the mech clamps and tighten.

06 Finishing touches

It is essential to fit end caps to all cables. Trim all but 5cm of inner cable protruding from cable clamps. Taking care not to splay the cable end, slide on an end cap. Crimp it gently with side cutters two or three times, and be careful not to slice through it. Alternatively, superglue an end cap into place. Finally, road-test your bike.