leob1

I have just installed a set of Avid BB5's on one of my bikes, my first disk brakes. I spent considerable time setting them up. But I'm not sure that I'm getting the best performance from them. I used regular spiral wound cable housing, would I get better brake performance by using compressionless(aka shifter) housing?

joejack951

STOP! Don't even think about using shifter housing for a brake. It is not radially supported and can literally split apart under braking forces. You couldn't even fit a brake cable into it anyway but I'm sure that hasn't stopped someone from simply using a derailler cable instead.

With that said, I'm currently using compressionless brake housing (by Jagwire: https://www.universalcycles.com/shopp...&category=4384) specifically intended for disc brakes. Honestly, if I hadn't been having problems with my set up (ended up just being a headset adjustment) I'd have never bought it. I can't say my brake feels anyway better with it though there may be some slight benefit.

The biggest benefit to disc brake performance that I've found is performing as accurate of a set up as possible allowing you to run both pads as close as possible to the rotor. You may need to put up with a slight amount of rubbing to get there as no rotor is perfectly flat and truing one to perfect flatness is not something I've been too successful with.

FBinNY 

No.

Unless made with a ballistic outer cover, usually kevlar, high helix index housing is not suited for brake applications because under high compression the strands can and will buckle causing total loss of brakes.

Index (high helix) housing is for derailleurs and designed for precise transmission of position at low loads
Brake (low helix) housing is for brakes and designed for reliable transmission of force at all loads.

If you haven't kinked the housing separating a coil, than any slop you might have might be from poor cuts or incorrect ferrules. One indicator is if the housing deflects sideways at the fittings when you apply the brake. If so, pull it apart and square off the ends with a grinder (work fast and quench often so you don't melt the plastic cover or liner).

leob1

Learn something every day, compressionless houseing isn't the same as shifter houseing. I was under the (mistaken) impression that because they have similar construction they where interchangeable. I'll give it some time, and if I ca't stand it, I'll try the compressionless housing.
I usually cut my housing with a Dremel with a cutoff wheel, cuts it square and smooth. You just have to shape the plastic with your fingers.
Thanks.

FBinNY 

The terminology can get confusing sometimes and may be used differently in various places.

High helix, or long spiral housing is where the strands run almost lengthwise with a slight twist. This was introduced by Shimano who called it compressionless, because it doesn't change the length on the channel when flexed and thus is ideally suited for index shifting. Folks today call it gear or derailleur or index housing. Generally it is unsuited for brakes because of the potential for total failure, but there is high helix brake housing where they wrap it in another layer of steel or kevlar ro support the strands from buckling.

So there is "compressionless" brake housing, but it has to be specifically made for the job. Otherwise "compressionless" housing is gear housing as you first thought.