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Bicycle shifter, brake cable, and housing standards

Updated: 17/02/2021.

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
  7. My shopping recommendations


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

Important note: Shimano seels (at least here, in Serbia) two shifter housing models:

  • Shimano SP40 SIS. This one doesn’t work very well and I don’t know what it is good for. On the outside, it looks like the proper shifter housing: is only 4 mm wide (brake housing is usually 5 mm wide), and has SIS (Shimano Indexing System) written on it. But, it has a spiral steel “skeleton,” like the one used in brake housing – stronger, but more flexible.
  • Shimano OT-SP41 SIS. This is the proper shifter housing. It is also 4 mm wide (outer diameter), but has the longitudinally lined steel wires, making it stiff in terms of shifter cable for-aft movement, resulting in more precise shifting. See picture 8 below for the difference between this, and brake housing “skeleton.”

SP40 does work a bit better with shifters, compared to brake housing (low-end bicycles sold locally often come with brake housing used for both brakes, and shifters). But it is still inferior to OT-SP41 in terms of shifter precision.


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, and 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.


7. My shopping recommendations

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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10 thoughts on “Bicycle shifter, brake cable, and housing standards”

  1. Excellent article.
    Any idea why cable housings labelled “Shimano SIS” would be spirallly wound (like brake cable housings)?
    I was about to replace my shifter cables using the the housings with these labels, thinking that they would have to be shifter housings until I checked them a little more closely

    Reply
    • Can I swap that question for an easier one? Higgs boson, black holes, relativity theory? Because cycling industry engineering, powered by cycling industry marketing is a mystery for the 22nd century minds to resolve. 🙂

      On a more serious note:
      Here, in Serbia, Shimano sells shifter housing that is 4 mm wide (outer diameter), has the spirally-coiled steel inserts, like brake housing, and is labeled as Shimano SP40 SIS.
      They also sell what I consider the proper shifter housing, also 4 mm wide, labeled as Shimano OT-SP41 SIS.

      In my experience, SP41 works more precisely, better, in practice.
      But SP40 does work a bit better than the brake housing (I often see brake housing used for shifter cables, on the brand new low-end bicycles sold locally).

      I’ll edit the article with this info – think it’s important to note, and avoid any confusion.

    • not all cable housing is the same,cables labled shimano sis are much stiffer cable housing and its basically used for modern road bike shifters,some cable housing is 4mm thick and some cable housing is 5 mm thick.brake cables for a mountain bike is more flexable and 5 mm thick,all brake cables have that internal spiral pattern.when purchasing mountain bike cables its a different setup to the modern road bike cables altogether.

  2. Thanks for the clear answer.
    How about some worked solutions to a few Navier-Stokes problems?
    Following your confirmation, just replaced all shifter cables with OT-SP41, although the bike shop made a 500% mark up. Buying in bulk from now on.
    Cheers
    Geoff

    Reply
    • all shifter cable has long straight strands,no spiral pattern at all,and shifter cable housing are much tougher than brake cable housing and they are more thiner.

    • if you see a cable labled shimano sis and it has a spiral pattern it is a modern road bike brake cable,i made a little mistake in my other post.most modern road bike break cables are much firmer then mountain bike brake cables

    • Probably the most useful piece of bicycle-mechanics related advice. If I could, I’d keep this comment pinned on top of all the other comments.
      After all: “cleanliness is next to godliness!”

      🙂

  3. The Shimano SIS-SP41 shifter cable housing has been pre-lubricated over its entire length with a special silicone lubricant. This reduces cable resistance by 10% (compared to SP40) and guarantees fast, precise shifting. It is not necessary to grease the cable when installing.

    This is from a Shimano brochure

    🙂

    Reply

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