Compressionless brake outer

[Samuel D]

The usual effect of this is that the cable housing adopts (where possible) a single radius rather than a compound radius when the inner cable is under tension. There is a length change associated with this change of shape.

The length change seems small, though, in that you can waggle a cable in this way by varying the lever pressure with barely any travel.

So do curved sections of compressionless housing not waggle at all in search of a single radius when the brake is applied? Probably I should get some of the stuff and see all of these effects for myself.

The effects of cable sticking friction are distributed differently when the housing compresses vs when it doesn't. This may alter the way the cable feels, even if the coefficient of sliding friction is the same.

Good point.

I replaced the spiral outer with linear brake outer (Jagwire) and the problem was solved, so it works.

That’s pretty clear. Thanks.

[Brucey]

The usual effect of this is that the cable housing adopts (where possible) a single radius rather than a compound radius when the inner cable is under tension. There is a length change associated with this change of shape.

The length change seems small, though, in that you can waggle a cable in this way by varying the lever pressure with barely any travel.

So do curved sections of compressionless housing not waggle at all in search of a single radius when the brake is applied? Probably I should get some of the stuff and see all of these effects for myself...

I think that it waggles less and with a smaller length change too.

I think that compressionless outers are usually better than spiral wound, especially if there are other sources of flex in the braking system anyway; it can reduce the total flex. But having said that, replacing cables with nice new ones (of any sort) that are well-prepped and lubed usually has a beneficial effect, much of which is likely to be attributed to the nature of the cable rather than its newness. IMHO a new, well prepped cable of any kind is liable to be a significant improvement over an old one of any kind.

cheers

[gloomyandy]

One point worth mentioning is that the compressionless cables (at least the Jagwire ones I've used) are considerably less flexible than the more traditional ones to the extent that they may not like following some curves. They often come with a special section for use under the bar tape that is designed to follow the tight curve there more easily. When I used them on one of my bikes with conventional brakes I gave up trying to use the Jagwire outer for the short section from the rear brake caliper to the cable mount on the top tube. I just couldn't get it to follow the curve correctly and be able to move with the caliper when the brake was applied. Instead I used a section of conventional cable with no problem.

[MikeDee]

What about those link type cable housings like Nokon makes? Are they even stiffer than compressionless outers?

[gloomyandy]

When you say stiffer do you mean less compression or easier to route round a curve? I have a friend that has used them on a TT bike and I'd say they are easier to get to follow a curve. No idea how they compare in terms of compression.

[MikeDee]

When you say stiffer do you mean less compression or easier to route round a curve? I have a friend that has used them on a TT bike and I'd say they are easier to get to follow a curve. No idea how they compare in terms of compression.

Less compression.

[Mr Evil]

...So do curved sections of compressionless housing not waggle at all in search of a single radius when the brake is applied?..

I use Nokon cables, which are compressionless, and no, they don't waggle at all. It's pretty weird really - I can bend them into any shape, even a totally suboptimal wavy shape, and they will stay like that.