Maintaining and replacing the gear cables on a mountain bike is very
similar to caring for cables on a road bike. However, mountain bikes
are often subjected to harsher conditions than road bikes so the cables
must be replaced and lubricated more regularly.
Take special care with the cable disc brakes of a mountain bike because
they have longer lengths of cable housing and the cables require lubricating
Rear gear cables can slap against the frame when you ride a mountain
bike over rough ground. If this happens regularly, it may mark the paintwork,
so try putting tiny rubber rings over the exposed cable to protect the
Above: Parts of gear-shift units include:
- SRAM Grip Shift: Barrel adjuster, Shifter body, Cable port, and
- Shimano Rapidfire: Gear-shift levers, Ring clamp, Barrel adjuster
Replacing a Rapidfire
the old cable with needle-nose pliers and put the shifter in the smallest
cog or chainring position.
- Insert the end of the new, lubricated cable into the hole where
the cable nipple sits inside the shifter.
- Check the route of your existing cable and follow the route when
fitting a new cable in Step 4.
both the cable and cable housings with your cable cutters to the same
length as the old ones. Make the housings long enough to let the cable
travel freely inside.
- Dribble a drop of oil down each cable housing.
- Fit a ferrule to the end of each cable housing to ensure that it
fits tightly into the frame’s cable guides.
Push the cable into the hole until its end shows through the barrel adjuster
on the outside of the shifter body.
- Thread the cable through the first length of lubricated cable housing.
the inner cable through each length of cable housing.
- For a rear derailleur, unscrew the barrel adjuster to about half
its range and insert the inner cable. For a front derailleur, put the
cale into the clamp.
- Pull hard with your cable pullers and tighten the cable clamp. Cut
off any excess cable.
Replacing a Grip Shift gear cable
(1) Put the rear shifter into the smallest cog and the front shifter
into the smallest chainring.
- Lift the cable port to reveal the old cable and remove it with needle-nose
- Spray a small amount of light oil into the mechanism while the port
(2) Grease the new cable, insert it into
the Grip Shift, and push it until the end protrudes from the other side
of the shifter.
- Thread the cable through each housing and secure to either the front
or rear derailleur as in Step 4 for Replacing a Rapidfire gear cable.
- Replace the cable port, cut off any excess, and put a cable crimp
on the cable end.