difference between brake and gear cable housings

[scottyj]

I have such a jumble of cable housings in the shed, none labelled and cannot really tell which is brake or which gear cabling. Internal diameter doesn't seem much different. Is there a difference and how do I tell, or does it even matter? thanks. Scott J

[sogood]

IIRC, construction of the housing is different. You'll see it if you examine it closely at the cross section.

[il padrone]

Brake cable housing is made from one coiled square-section wire. At the cut end you'll only see one wire, spiralled around the housing.

Gear cables (for modern STi) are made of a large no. of longitudinal wires. At the cut end you'll see these multiple small wires' ends.

Yes, it really does matter! Old-school gears used the same coiled housing as for brakes. However indexing for STi demands greater cable-tension consistency, so the housing must be able to resist compression.

[familyguy]

Brake cable is generally (not always) a little larger in outside diameter because of the coiled internals. Modern gear cables (longitudinal wires) can explode if used for braking cause the force is not directly along the cable sheath. See here.

Jim

[scottyj]

many thanks. Have had a look at them and they all seem coiled, so off to the LBS I go. cheers. Scott J

[Dan]

Reviving an old thread, as I ordered brake cable outer from CRC and was sent what appears to be compressionless gear cable outer, with longitudinal wires as opposed to the traditional spiral construction. Thing is, its 5mm OD like brake cable outer, and is labelled (albeit via sticker) as brake outer. Brand is Goodridge.

I have read the literature surrounding the risks of using compressionless for braking systems - questions as follows:

1. Have there been tech advances which now allow the use of compressionless housing for braking; and
2. Is there an application anywhere for 5mm gear cable outer? If not, it would indicate that this is purpose designed brake outer.
EDIT: further reading says there is indeed 5mm gear outer, which means I've likely been sent gear outer in place of brake outer.

Easy enough to zip up to the LBS and get brake outer, but that's not really the point.

Il Padrone, you there?

[il padrone]

Yes, if it's compressionless gear cable housing I'd save it for that use. Easy enough to get regular brake cable outer - it is usually a lot cheaper in price - so I'd visit your LBS. Better to err on the safe side here.

[Dan]

my thoughts too. thanks for confirming.

[Jesmol]

Yokozuna Brake cables are a combination of the compressionless gear style tubing, bound together by spiral wound wire, when you cut it , it looks like gear cable.

[Dan]

It appears the Goodridge cable outers are a braided construction, suitable for braking applications. Hmmm.



EDIT: can't find the random external forum link that stated this. Sorta says something...

[il padrone]

You should be able to see the difference between cut braiding (which is just poly fibres) and cut gear cable (steel wires). I'd also [i]expect[/b] their braided brake cable will still have the spiral-wound wire housing as well.

[Dan]

I wasn't entirely clear in my last post, apologies. The more I look for info about it, the more it appears the longitudinal steel wires could actually be the braid, and not laid longitudinally as a with typical compressionless housing. Or maybe I just want this to be the case. Typical interwebz search - loads of conjecture, but nothing definitive, and SFA from the manufacturer themselves.

I don't recall seeing an additional layer of braid over the small cables at the cut end, but to me honest I was too busy being annoyed at potentially having been sent the wrong thing to be paying attention to details like that

I'll have another look tonight, but safe to say I'll be collecting normal outer on the way home... I think its the wrong product. Agree with you IP that the brake cable should have the bowden cable, and what I was supplied most definitely did not have it. Further reading suggests the Goodridge gear cables are a nominal 5mm OD, which more than likely explains the mixup.

Link to CRC description here.

[jules21]

It appears the Goodridge cable outers are a braided construction, suitable for braking applications. Hmmm.

the steel wiring is underneath the plastic outer. if you look at it from a longitudinal perspective, you should see the outer (as pictured above), the steel cabling (which is how you discern whether it's gear or brake cable), and then an inner plastic sheath (usually clear).

[Dan]

I also think I need to clarify that I know what a traditional version of each cable should look like - what I'm trying to ascertain is if Goodridge are using a longitudinally arranged (or a braided derivative thereof) construction as their brake cable outer. I suspect not.

[Mulger bill]

Don't quote me on this because it's all old IIRC stuff...
Pretty sure I read one makers blurb saying they made incompressible brake outers because it "offered better feel".
A quick google hasn't helped as I've no idea of the makers name.

EDIT. Jagwire it seems.

[biker jk]

Don't quote me on this because it's all old IIRC stuff...
Pretty sure I read one makers blurb saying they made incompressible brake outers because it "offered better feel".
A quick google hasn't helped as I've no idea of the makers name.

EDIT. Jagwire it seems.

Yes Jagwire brake housing using compressionless gear style tubing. I just checked mine.

[eeksll]

This rings a bell.

I also purchased goodridge brake cable outer a while ago, I got the set, not the "by the meter" stuff ... i.e. this one

They are extremely stiff and didn't work for the tight bends I needed so I still have the set cable set (cut obviously), just had a look, it is of what appears to be the stranded variety.

I just had a google ... you are not the only one to notice ...
Not 100% sure if I follow the conclusion they make here ... ie are the saying its "braided" not stranded so that makes it ok?
http://www.bikeradar.com/forums/viewtop ... p=15063179

http://newsgroups.derkeiler.com/Archive ... 02164.html

http://www.bentrideronline.com/messageb ... p?p=698463

... quite a few more too

so either its intentional and will be fine or maybe they made one bad batch and they are still floating around in stores? I'd think most likely the former, but its your neck not mine.

I only had mine on as brake cable outers for a very short period (as they where so stiff they messed with the balance on my v brakes) so I can not attest to longer term use. Initial thoughts where "not spongy what so ever". Maybe email goodridge or CRC (or both) and get it sorted.

[Dan]

Grabbed some outer on the way home (thanks gypsy) so cut a piece of the goodridge to strip off and check. Its definitely 5mm gear outer - no Bowden casing underneath.

I'll not be using it for brakes - the post above shows the typical Internet scenario where no one actually knows what's going on.

Endnote: I emailed CRC yesterday - they were extremely apologetic and are sending a replacement FOC.

[il padrone]

This makes the most sense to me:

We've come a full circle.

Back in the days when men were men and bikes only had 10 gears there wasn't any difference between brake and shift cable housing.

When index shifting came out, shift cable housing compression became an issue so a different housing had to be used for shifters. Since brake cable tensions are much greater, spiral wound cable housing was still necessary for brakes. Consequently you had to use the right housing for each purpose.

Then cable disc brakes came out. They don't work so good with ordinary spiral wound cable housing. It's possible today to obtain cable housing that works equally well with either shifters or brakes.

Disc brake cable runs may involve less bends than a conventional V-brake or dual-pivot brake cable, and may use less cable pressure.

[alex]

I also think I need to clarify that I know what a traditional version of each cable should look like - what I'm trying to ascertain is if Goodridge are using a longitudinally arranged (or a braided derivative thereof) construction as their brake cable outer. I suspect not.

i have used the goodridge housings before, the inside looks like any other housing and they feel the same as any other housing, the braiding on the outside seems to be purely cosmetic

[takai]

I use the Goodridge stuff as well, both brake and gear cable on the different bikes. Its a braided outer casing, on an inner spiral wound shell with a teflon liner.

They use the same construction for both the gear and brake outers, only the teflon liner ID changes.

Jagwire on the other hand use a braided liner over a compressionless segmented steel inner. Pain in the arse to cut.

[human909]

Yes, it really does matter! Old-school gears used the same coiled housing as for brakes. However indexing for STi demands greater cable-tension consistency, so the housing must be able to resist compression.

This is a bit misleading. But that is more shimano's fault for talking about SIS "compressionless" housing. Brake housing actually resists compression far more than gear housing. Having stiff cable that resists compression is very desirable for brakes as the compression forces are high. Stiffer cables means stiffer brakes, there is a very noticeable performance difference between cheap brake housing and the better stuff.

Gear housing's most desirable characteristic is to not change length when it is bent. Otherwise the simple act of turn the handle bars could change your gears!


Different needs different products.

[il padrone]

I use the Goodridge stuff as well, both brake and gear cable on the different bikes. Its a braided outer casing, on an inner spiral wound shell with a teflon liner.

They use the same construction for both the gear and brake outers, only the teflon liner ID changes.

Jagwire on the other hand use a braided liner over a compressionless segmented steel inner. Pain in the arse to cut.

Gear cables using the old spiral wire ?? Unlikely to get reliable shifting from that, unless they've made some design breakhrough.

Cutting the compressionless cable is easy, with the right tool - a hook-jawed cable cutter

[il padrone]

This is a bit misleading. But that is more shimano's fault for talking about SIS "compressionless" housing. Brake housing actually resists compression far more than gear housing. Having stiff cable that resists compression is very desirable for brakes as the compression forces are high. Stiffer cables means stiffer brakes, there is a very noticeable performance difference between cheap brake housing and the better stuff.

I have seen what happens to older compressionless cable housing when it fails under gear shifting loads. I would not want that to happen when I'm on the brakes. Never seen any brake housing fail.

[human909]

I have seen what happens to older compressionless cable housing when it fails under gear shifting loads. I would not want that to happen when I'm on the brakes. Never seen any brake housing fail.

Yes I recently replaced a blowout of gear housing on my beater commuter bike. I was a little confused about my shifting problems until I noticed that the gear cable had begun taking a shortcut around the curve in the housing.

Still given that the housing was over 13 years old I could hardly complain!