MTB derailleur cables and housings

How to choose MTB gear cables and outer casings

On a mechanical drivetrain, shifting precision depends as much on the cable as on the derailleur. A cable that rubs results in gears that shift up poorly and shift down late. Shimano and Clarks offer both cable-only and complete kits.

Gear cable or brake cable?

• They are two different parts : the gear cable is thinner (1.1 to 1.2 mm) and has a smaller head.
• A brake cable will not fit into a gear shifter, and the reverse would be dangerous.
• Always check the description before ordering: mistakes are common.

Which outer casing?

• Gear outer casings have longitudinal wires : they do not compress, which preserves indexing.
• Never use a brake outer casing instead: its spiral winding compresses and throws off adjustment.
• A inner liner coated cable or a sealed outer casing significantly limits mud ingress, useful on frames with internal routing.

Cable only or complete kit?

• The cable only is enough if the outer casing still slides freely and is neither split nor pinched.
• The complete kit includes cable, outer casing, end caps and cable guides: the logical solution after a wet season.
• A cable stainless steel or coated (such as Optislick) slides better and resists corrosion.

When should they be replaced?

A frayed cable at the shifter, a stiff spot in the cable travel or a derailleur that no longer returns cleanly to the smaller sprockets: these are the three classic signs. Expect to replace them once a year with regular use, twice as often if you ride in winter.

See also: MTB gear shifters · MTB rear derailleurs · MTB brake cables and housings