Compressionless cables ?

[on6702]

Can someone please enlighten me?

In particular what they actually, how they work and what function do they serve?

I have yet to find a clear description on the internet. Does it mean that they are crush proof to help protect the inner cable or is it actually something else? e.g reduced friction?

Various blogs / websites sing the praises of such cables and claim better braking but it's not clear to me why they are superior?

Lastly, I need to replace the cabling on my front v brake on my hybrid as it feels stiff and creaky. Would I benefit from using this type of cable?

Oliver

[gloomyandy]

They do not compress (as much) end to end. So when you apply force to the brake lever more of that force ends up actuating the brake rather than shortening the overall length of the brake outer cable. This may or may not hep with your problem, but in general because the cable length for a front brake is so much shorter they do not help as much with front brakes as they do with rear ones.

[meic]

I looked yesterday and found somebody selling half of an outer cable set for £25 on ebay.
Cut carefully might do front and rear.

Apart from that kits for £40, not sure if they were in this country.
I do have a problem with paying for £40 for some brake cable outers for one bike!

I think I will put up with the rubbing disc instead (assuming the cables would actually cure it).

[531colin]

The outer doesn't compress along its length, so you get less lost motion, not less lost force, and not less friction.
Vee brakes have a low force on the cable, and a long pull....bowden cables work much better "long pull, low force" than "high force, short pull" .....as in dual pivot sidepulls.
For a front Vee brake with a short cable, long pull, and low force, you don't need compressionless cable.

[le.voyageur]

please correct me if I'm wrong but I think they're only really required for mechanical non hydro disc brakes?
I have them fitted on two bikes with mechanical discs, never had non compressionlss but I've read discs with normal cables can and often do feel mushy.

[cycleruk]

Compressionless cables are only for use on gear changers (dérailleurs).
That is unless they are specifically made for brake systems.

A compressionless outer has the strands of wire running straight and parallel as opposed to brake cable outers which are run in a spiral along its length.
Using a compressionless outer on brakes runs the risk of the inner cable bursting through the outer when under braking pressure.
Not only that but gear cable/outers are usually thinner than brake ones. You can use a brake outer on gears but the changing may not be as good.

[reohn2]

When I built my first bike with cable discs(BB7 road calipers,Tektro RL340's and Tektro crosstop levers)I'd never heard of compressionless brake outers.
Everything worked very well indeed,with great stopping power and excellent modulation and they still do
I also bought an almost new S/H Kona Dew Drop,same brakes with Sora 8sp STI's,to which I also fitted Tektro cross tops,and which I later discovered didn't have C/less outers either(I strongly suspect they were original equipement) they worked well too .

[Roadster]

Compressionless cables are only for use on gear changers (dérailleurs).

The Jagwire Sport cable set I bought was indeed supplied with "coiled" outers on the brake cables and a "linear" (compressionless) outer on the gear cable only. As I pointed out in this earlier thread, however, a gear cable with "linear" outer is of benefit not just to derailleurs but also to hub gears, especially those with multiple ratios like my Alfine 8:-
viewtopic.php?f=5&t=110890&p=1076468&hilit=jagwire#p1076468

[foxyrider]

Not sure where the idea that 'linear' outers shouldn't be used for brakes. Quite the opposite, they can dramatically improve brake performance on many bikes and brake set ups. Wound outers will compress under braking giving spongy performance, a change to linear will usually give sharper performing brakes - even with some of the cheesy vintage brakes.

OTOH wound outer is the usual stuff for gears although linear outer is available. Some gear shift systems may gain by using linear but it's not a given - we aren't relying on the outer to make the system work.

Linear is more expensive, whether you think it's extra performance is worth the cost will be an individual thing. As I like the best operating bikes I can manage, new cables & outers each year are a small price to pay.

[cycleruk]

Not sure where the idea that 'linear' outers shouldn't be used for brakes. Quite the opposite, they can dramatically improve brake performance on many bikes and brake set ups. Wound outers will compress under braking giving spongy performance, a change to linear will usually give sharper performing brakes - even with some of the cheesy vintage brakes.

OTOH wound outer is the usual stuff for gears although linear outer is available. Some gear shift systems may gain by using linear but it's not a given - we aren't relying on the outer to make the system work.

Linear is more expensive, whether you think it's extra performance is worth the cost will be an individual thing. As I like the best operating bikes I can manage, new cables & outers each year are a small price to pay.

You have not read above properly. A linear outer can burst open under the excessive cable force that brakes can exert, so could be a safety issue. You may have brake improvement until they completely fail.
A coiled outer will compress a little which can upset indexed gear systems so are not the "usual stuff".

If you look closely at Shimano cables you will realise there is a difference between gear and brakes or I'm sure that Shimano wouldn't bother making the two types.
Unless linear outers are specifically made for brakes, linear outers are usually narrower than brake outers. Brake inner cables are thicker than gear cables so will probably be subject to drag inside a linear gear outer.
Shimano normally have "STI" embossed on their gear cable.
Modern Campagnolo also advise using the appropriate cables for their gear systems.

[531colin]

Compressionless BRAKE outer.....for brakes....

[foxyrider]

Not sure where the idea that 'linear' outers shouldn't be used for brakes. Quite the opposite, they can dramatically improve brake performance on many bikes and brake set ups. Wound outers will compress under braking giving spongy performance, a change to linear will usually give sharper performing brakes - even with some of the cheesy vintage brakes.

OTOH wound outer is the usual stuff for gears although linear outer is available. Some gear shift systems may gain by using linear but it's not a given - we aren't relying on the outer to make the system work.

Linear is more expensive, whether you think it's extra performance is worth the cost will be an individual thing. As I like the best operating bikes I can manage, new cables & outers each year are a small price to pay.

You have not read above properly. A linear outer can burst open under the excessive cable force that brakes can exert, so could be a safety issue. You may have brake improvement until they completely fail.
A coiled outer will compress a little which can upset indexed gear systems so are not the "usual stuff".

If you look closely at Shimano cables you will realise there is a difference between gear and brakes or I'm sure that Shimano wouldn't bother making the two types.
Unless linear outers are specifically made for brakes, linear outers are usually narrower than brake outers. Brake inner cables are thicker than gear cables so will probably be subject to drag inside a linear gear outer.
Shimano normally have "STI" embossed on their gear cable.
Modern Campagnolo also advise using the appropriate cables for their gear systems.

Forgive my ignorance, i've only been working in the trade twenty odd years so the fact -i've never seen this cable burst business and sold hundreds of linear BRAKE cables clearly is immaterial.

I bow to your superior knowledge

[PT1029]

I used to think linear stranded cables were only for gear cables, second the comment that gear indexed outers used on brakes fail by bursting open (quite quickly too...).
Compressionless brake outer is made, having removed some (original fittings) off a Specialized road bike (the inners had got gunged up, outer hadn't failed).
It is expensive, but I did have great squidgyness issues with a rear Avid BB7 disc on our tandem (it either rubbed on the disc or had excessive lever pull). Fitting the compressionless outer got it sorted.
I expect for most applications, it might make things a bit better but isn't really necessary for most set ups.

[cycleruk]

Forgive my ignorance, i've only been working in the trade twenty odd years so the fact -i've never seen this cable burst business and sold hundreds of linear BRAKE cables clearly is immaterial.
I bow to your superior knowledge

Nothing to do with my knowledge. Just supposing a new someone coming on the forum and seeing that it's all right to use linear cables not realising that there are two types. They may fit the wrong type. This is a safety factor unless explained properly.
Yes there are linear brake cables but that was not explained up front.

[Caulkheader]

Fit Jagwire compressionless cables to a Boardman CX with drops and Avid mechanical discs. Vast improvement in feel and modulation. Brakes are no longer spongy. Not cheap but I think money well spent.