Brake cables

BMX brake cable and housing: the part everyone forgets

Riders replace their pads, fuss over the caliper, then keep a frayed inner wire running through housing full of grit. That is exactly where half the feel and a good share of the power disappear: a fresh cable in clean housing turns a spongy brake into a sharp one without changing a single expensive component.

The inner wire: diameter, material and nipple

A brake inner wire measures 1.5 mm in diameter against 1.1 mm for a gear wire, and the two are never interchangeable. It comes in galvanised steel, which is cheap and perfectly serviceable, or in stainless steel, smoother and far more resistant to corrosion on a bike that gets jet-washed after every meeting. Polymer-coated versions cut friction further through tight bends. The nipple has to match the lever: in BMX Race that means a barrel nipple of the MTB type, never a pear-shaped road nipple.

Housing and small fittings

• Brake housing with a 5 mm outer diameter, helically wound, with a PTFE liner inside.
• Compressionless housing with longitudinal strands, firmer under load and recommended with a cable disc brake.
• Ferrules in 5 mm, essential so that the cut end does not crush the liner.
• Noodle and rubber boot, specific to the V-brake.
• Crimp end caps, to stop the inner wire fraying at the pinch bolt.

Length and cable routing

Since the rear brake is the only one fitted, the useful length is measured from the lever to the caliper. There are two schools of thought: full-length housing, which protects the wire over the whole run and copes far better with mud, and a cut-housing build using cable stops on the frame, which is lighter and visually tidier. Always cut housing with a proper cable cutter, then reopen the liner with an awl — housing crushed with side cutters creates a permanent dead spot.

Compatibility

A mechanical cable works equally well on a V-brake caliper and on a cable-actuated disc caliper: same diameter, same nipple. A hydraulic system, by contrast, uses no cable at all but a fluid-filled hose supplied with the kit — see our disc brake kits. Finally, check that the nipple matches your brake lever, which is the only genuinely blocking point.

Use and colours

On a training bike ridden in all weather, full-length housing and a stainless inner keep maintenance down. For racing, riders tend to prefer a coated wire and short housing runs for feel. Housing is available in most colours, which lets you match the build to the frame and to the rest of your finishing kit — a detail that shows on a well-prepared bike.

When to replace

Replace the inner wire as soon as a strand breaks, as soon as rust appears near the pinch bolt, or if the lever returns slowly after you release it. Once a season on a bike ridden regularly, it is a few euros of maintenance for an immediate gain in feel.

The BMX RACING advice

We supply inner wires, housing and fittings individually as well as in kits, so you do not buy the whole set when only the wire is finished. Unsure which nipple suits your lever? Send us a photo and we check it before dispatched within 24 to 72 hours.