Road bike gear cables and housing

Cable and housing: the pair that controls your gears

On a road bike with a mechanical drivetrain, the precision of your gear changes depends as much on the cables as on the shifter or the derailleur. The inner cable, held in the shifter by its head, pulls the derailleur; the housing, or outer, guides it to the frame and acts as a support so that the pull is transmitted without loss. A cable that rubs, or housing that is crushed or dirty, and the whole indexing goes out of adjustment: hesitant shifts, a chain that hangs between two sprockets, a stiff shifter. On road bikes, where the housing comes out of the hood, runs under the bar tape and then often inside the frame, this friction quickly adds up.

Gear cable or brake cable: do not mix them up

• The gear cable is thin, with a small cylindrical head that sits in the shifter; the head differs between brands, with Campagnolo using its own format.
• Gear housing, around 4 mm in diameter, is made of steel strands running parallel to its length: it does not compress, which keeps the indexing precise.
• Brake cable and housing are thicker; brake housing, wound in a spiral, withstands the force of hard braking without bursting.

Brake housing used for gears compresses and makes the indexing imprecise; gear housing used for a brake can burst under the load. Each use therefore has its own housing.

Coatings, internal routing and electronic drivetrains

Galvanised cables are the simplest, stainless steel cables resist corrosion better, and cables coated with polymer or PTFE slide with less friction inside the housing, at the cost of a coating that eventually wears. Much housing has a thin, smooth liner built in, which means it does not need greasing. On frames with internal routing, a guide sleeve slipped into the tube helps the cable come out in the right place, while cable stops guide the cable on frames with external routing. Electronic drivetrains replace these cables with electrical connecting wires, specific to each system.

Road bike gear cable replacement: when and how?

Replace them when the cable frays or rusts, when the gears no longer hold their adjustment despite the barrel adjuster, or when you change shifters or handlebars. Cut the housing square with cable cutters, reopen the end with an awl, then cap each end with a ferrule. The bends should stay gentle and not pull on the handlebar when you turn. After a few rides, a new cable beds in slightly: a small turn of the barrel adjuster restores the indexing. A new cable is then adjusted on the road bike derailleur, and persistent trouble may come from the road bike shifter itself.

Cables and housing for other kinds of riding

For braking, spiral-wound housing is gathered in MTB brake cables and housing and gravel brake cables and housing. Mountain bikers will find their gear cables in MTB gear cables and housing, and all road drivetrain parts are brought together in road bike drivetrain.

Which gear cable and housing brands to choose?

Shimano offers coated Optislick and Polymer gear cables, stainless steel cables individually or by the box, complete road cable and housing sets, and small parts for its shifters and derailleurs, such as adjuster screws.

Jagwire, a control components brand that makes cables, liners, hoses and brake pads, sells its derailleur cables in complete kits to fit yourself, Road Elite, Elite and Pro, in single or double chainring versions.

Sram offers its Slickwire derailleur cable, 4 mm derailleur housing sold by the metre or in a workshop roll, and ferrules sold in packs.

Campagnolo supplies stainless steel derailleur cables designed for its Ergopower shifters, individually or by the box, and a cable kit for its EPS electronic drivetrain.

Gear cables and housing at reduced prices

End-of-line kits and boxes are grouped in road drivetrain clearance, and the latest parts to arrive can be found in new arrivals. Replacing cables and housing over the winter avoids nasty surprises on the first rides of the season.

Frequently asked questions

Can you use brake housing for gears?

No. Spiral-wound brake housing compresses slightly under tension: fine for a brake, but enough to upset the indexing of a derailleur. Use gear housing with longitudinal strands, and keep spiral-wound housing for the brakes.

What length of cable do you need for a road rear derailleur?

Derailleur cables are generally sold at around two metres or more, enough to connect the shifter to the rear derailleur on most frames; you simply cut off the excess after adjustment. Longer cables exist for tandems.

Are Shimano cables suitable for Campagnolo shifters?

Not always, because the cable head is not the same shape. Choose a cable stated as Campagnolo compatible, or a cable supplied with both heads, to be cut to suit the shifter.

Should you lubricate a gear cable?

A coated cable fed into housing with a smooth liner is fitted without grease, which would attract dust. A bare steel cable in housing without a liner, on the other hand, benefits from a thin layer of light lubricant. Follow the manufacturer's instructions.

Should you change the housing at the same time as the cable?

It is advisable: worn or dirty housing cancels out the benefit of a new cable. Cable and housing kits make the job simpler and supply the right ferrules.