Derailleur (shifter) cable and housing routing

Shifter and brake cable and housing standards

Updated: 04/10/2019.

This post’s topic are shifter and brake cable and housing standards. From my experience, many problems with poor shifting, or braking, come from using incorrect components. Separate post explains brake and shifter cable routing.

Contents:

  1. Shifter (derailleur) cable standards – differences
  2. Brake cable standards – differences
  3. Shifter housing standards
  4. Brake housing standards
  5. IMPORTANT: difference between brake and shifter housing
  6. “Exotic” models


1. Shifter (derailleur) cable standards – differences

Shifter cables have a barrel on one end, that is used for shifter to pull (and release) the cable, while the other end is soldered, so that wires don’t get unwinded and so that the cable can more easily be routed (and cut to the appropriate length after routing).

Shifter (derailleur) cables - with a barrel on one end and soldered wires on the other
Shifter (derailleur) cables – with a barrel on one end and soldered wires on the other
Picture 1

Shifter (derailleur) cables come in two standards, main difference being the end barrel, though cable thickness also tends to differ:

  • Campagnolo standard – 1.1 to 1.2 mm cable diameter, with a bit smaller diameter barrel at the end
  • Others (Shimano, SRAM…) – around 1.2 to 1.3 mm cable diameter – with end barrel a bit larger than Campagnolo one

Apart from the diameter, Campagnolo and Shimano shifter cables are visually almost identical, so pay attention to specifications when shopping (especially if you have Campagnolo shiters, since Shimano cables won’t fit Campagnolo shifters).

Difference between Shimano (left) and Campagnolo (right) shifter cables
Difference between Shimano (left) and Campagnolo (right) shifter cables
Picture 2


2. Brake cable standards – differences

To avoid/prevent any confusion, I’ll explain brake cables (and housing) as well in this post.

Brake cables come in three standards, with the main difference being the size and shape of the end barrel:

  • MTB – with a large barrel on one end
  • Road Shimano compatible – for Shimano and SRAM shifters
  • Road Campagnolo
Difference between brake cables for MTB (left) and road (right)
Difference between brake cables for MTB (left) and road (right)
Picture 3

With road cables, Shimano ones have a bit larger barrel, though very similarly shaped. In fact, some manufacturers (like Jagwire, for all I know) make road bike brake cable ends such that barrels are a bit on the smaller side, hence the same model fits both Shimano and Campagnolo brake levers.

Road bike brake cable ends for Shimano (left) and Campagnolo (right)
Road bike brake cable ends for Shimano (left) and Campagnolo (right)
Source: bikehub.co.za forum
Picture 4


3. Shifter housing standards

For shifter housing there are two standards:

  • Shifter housing with 4 mm outer diameter.
  • Shifter housing with 5 mm outer diameter (the same diameter, but not the same type, as brake housing).

All the shifter cables will run with no problems through housing by any of the above noted standards. Some MTB riders prefer 5 mm housing, since it leaves more room, so they don’t get stuck with mud that easily. Though, for 4 mm shifter housing, Shimano makes seals that prevent the entrance of dirt:

Plastic housing ends with rubberized seals for 4 mm shifter housing
Plastic housing ends with rubberized seals for 4 mm shifter housing
Picture 5

For 5 mm shifter housing ends, the same (metal) ends can be used as for brake housing (even though those are two different housing types!).

5 mm wide shifter housing (1) and brake housing (2) They look identical from the outside
5 mm wide shifter housing (1) and brake housing (2)
They look identical from the outside
Picture 6
4 mm shifter housing
4 mm shifter housing with a plastic end cap
Picture 7


4. Brake housing standards

With bicycle brake housing standards there aren’t any differnces – they are all 5 mm outer diameter with steel end caps. Apart from hydraulic brake hoses, of course, but that’s a different matter.


5. IMPORTANT: difference between brake and shifter housing

Too often I see brake and shifter housing mixed. But this is not good, can even be dangerous.

  • Shifter housing is constructed to compress and elongate as little as possible with shifter cable tension change (while shifting up and down). But it can not take large force – pull cable strong enough and it will split!
  • Brake housing is made to sustain very high cable tension forces without splitting, but slight compression is not as detrimental.
Intersection of cable housing. Left: brake cable housing Right: shifter cable housing
Intersection of cable housing.
Left: brake housing with a woven strong steel spiral.
Right: shifter housing, with steel wires running along the housing length, to minimize compression and elongation changes.
Picture 8
Left: brake housing cross section. Strong steel spiral makes the housing resist strong braking forces, but rather easily compressed and decompressed Right: shifter housing. Parallel steel wires prevent the housing from compressing (effectively changing length), but offer little resistance to high forces, so it can't be used as a brake housing
Left: brake housing cross section. Strong steel spiral makes the housing resist strong braking forces, but rather easily compressed and decompressed
Right: shifter housing. Parallel steel wires prevent the housing from compressing (effectively changing length), but offer little resistance to high forces, so it can’t be used as a brake housing
Picture 9
Left: brake housing, with strong steel spiral reinforcement. Right: shifter housing, with parallel longitudinally placed steel wires
Left: brake housing, with strong steel spiral reinforcement.
Right: shifter housing, with parallel longitudinally placed steel wires.
They are easily discerned by looking from “the front”, but one needs to pay attention.
Picture 10


6. “Exotic” models

There are special, braided brake housings that compress a lot less than “ordinary” brake housing, which is good – leaves more lever play and allows for more precise brake modulation. They are usually constructed using a layered combination of longitudinal steel wires and spiral steel, or kevlar lining to give more strength, so the housing doesn’t split when high braking force is exerted.

Such housing, due to less compression, can also be used for shifters. Though, for shifters, it is still a bit better to use shifter housing.

Their main downsides are somewhat higher weight and a lot higher price.

Special brake housing by Jagwire, with longitudinal steel strands and kevlar reinforcement
Special brake housing by Jagwire, with longitudinal steel strands and kevlar reinforcement
Picture 11


This sums it up. In case I’ve forgotten to mention something, or you have any corrections, or additions, use the comment section below.

On-line shopping (Amazon affiliate links):

Decent quality Shimano shifter housing
Decent quality Shimano shifter housing
Amazon affiliate link
Set of Campagnolo road shifter and brake cables and housing, by Jagwire
Set of Campagnolo road shifter and brake cables and housing, by Jagwire
Amazon affiliate link
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