xg5a

I'm currently building up a new All City Space Horse Disc frame, and this will be my first experience working on or installing disc brakes. I bought a set of TRP Spyre brakes, but I have a question concerning the cable housing during the install. I'm looking at these instructions:
https://www.trpbrakes.com/userfiles/...113%281%29.pdf

In section C, cable installation, they say:
- Install a small section of spiral wound housing that inserts into the brake lever body and runs inside or outside the first bend in the bar as shown. (Not all brake lever bodies need a ferrule installed - check with your brake lever manufacturer’s technical documents to determine if a ferrule is needed) The ends should be filed flat and the liner should be open to eliminate friction. Install a double-ended ferrule.
- Spiral wound housing can be cut to accomodate bar widths and preferences, such as hiding the double ended ferule under bar wrap. Allow spiral wound housing to extend at least 25mm, (1 inch) beyond the handle-bar bend.
- Install the compression-less housing on the remainder of the frame or fork. Cut accurately to minimize tight bends and acute angles to optimize the brake lever feel.
(check out the pdf for diagrams)

I'm a little confused by the whole part about the spiral housing. First of all, are they referring to standard brake housing as opposed to compressionless? Or do they mean some sort of brake noodle? Also what about the double-sided ferrule, is that a standard item? And is this standard procedure for disc brakes and compressionless housing or something unique to the TRP Spyre brakes?

By the way, here's the housing set I bought:
Jagwire Road Pro Complete Cable Kit > Components > Cables & Housing > Brake Cables & Housing | Jenson USA
It looks like it comes with some different ferrule types, maybe it has what I need? I have a ton of regular brake housing already as well.

Thanks for your help!

HillRider

"Spiral wound" means standard brake housing, not the "compressionless" shift housing which should never be used for brakes. So, yes, they mean standard brake housing. There is compressioless housing rated for brake use and that's what they want you to use for the housing run after the double-end ferrule.

Double end ferrules are used to connect two sections of brake housing and are available at your LBS or on-line. Here is one source: Jagwire Double-Ended Connecting Ferrule > Components > Cables & Housing > Brake Cables & Housing | Jenson USA

TRP wants you to use two joined sections of housing instead of a single full length housing run so the majority of the housing run is compressionless and gives a firmer brake action.

dsbrantjr

I have had good success fabricating my own double-sided ferrules by soldering two regular brass ferrules together end-to-end. Sand off the chrome plating for easier soldering and make sure that the holes are clear when finished.

xg5a

Interesting idea. Did you use a regular electronics soldering iron and solder?

dsbrantjr

Yep, 63-37 solder (I hate that lead-free crap) with an RMA rosin core. Brass solders really well if you remove the chrome plating. There is not really a lot of strength needed since the braking forces are pressing the ferrules together, the solder really just keeps them aligned.

xg5a

I was thinking the same thing as far as the braking forces. Do you know how to tell if a ferrule is brass vs. aluminum? I know for the cabling set I have one of the features is "allow ferrules" but I have a lot of random other ferrules so maybe one of them is brass.

AndreyT

It applies to either type. Compressionless brake housing normally has a segment of "standard" spiral housing attached at one end. That flexible end is specifically intended to be routed under the bar tape. Compressionless brake housing is too rigid to be routed around the bend in the bar, which is why they splice a short flexible spiral-wound segment on it.

So, in either case, it is going to be a piece of standard spiral-wound brake housing going into your integrated shifters.

That's exactly what you will find in Jagwire kit. Their brake housing is compressionless, but the bar end of each brake housing has a flexible spiral-wound segment. You can see it in the picture as silver segments at the end of each black brake housing.

dsbrantjr

Per AndreyT and the photo, you already have the ferrules in the kit, if not already installed. But to answer your question, chrome-plated brass is usually visually distinguishable from unplated aluminum; I generally take a file to the piece and check the color of the base metal if I am in doubt.

xg5a

Thanks for spotting that! I haven't opened the cable package yet, so I didn't realize I'm already all set. That's a lot easier!!!

And a follow up question after looking at the photo you pointed out: what's the deal with all of those other random ferrules in the kit, like the ones with the small spike sticking out of them? What are they supposed to be used for?

Metaluna

Here's a good explanation of all the Jagwire end cap types

Jagwire End Caps Guide | Jagwire

The "spike" is actually a tube that is supposed to protect coated cables from rubbing against rough edges in conventional ferrules and housing stops, and also provide a degree of dirt and moisture protection.

The "POP" ferrules (aka end caps) with the step-down diameter are designed to fit into housing stops (such as in some brake levers) that were designed to accept bare spiral housing without a ferrule, and thus are too narrow to accept the Jagwire end caps. Jagwire's compressionless housing needs special end caps to terminate it properly, so just sticking the bare housing into a lever body that was designed for spiral can cause problems, apparently. I even saw a YouTube brake setup tutorial recently where someone slid a conventional ferrule over the narrow section of the POP ferrule, I guess to either make it look better or to shim it out a bit.

xg5a

Thanks for the great info!


One more question for you guys: what's the best way to cut this compressionless brake housing? With normal spiral housing I've had good luck using a Dremel cutoff wheel to cut it, then using the Dremel's grinding wheel to grind the end flat, and then using a nail to open up the melted liner while it's still hot and soft. Can I use the same procedure here?

Crankycrank

Yes. If you have some old cable or even the unused end of a new cable you can insert it into the housing where the cut will be made and you won't need to open the melted plastic inner with a sharp object after you cut the housing.

Metaluna

The Jagwire stuff cuts pretty cleanly with a conventional housing cutter like the Park CN-10. When I do it, there are usually a few cottony strands of the Kevlar jacket that didn't cut through completely. Maybe a better cutter like a Felco C7 would take care of these but I haven't tried it. The strands can be snipped off with a scissors, and I think a few times I even just fanned out and folded them back onto the outer jacket before stuffing the whole thing into an end cap. Overall it's less fuss than trying to get a spiral cable dressed nicely.

What I don't know is if it matters whether you should do the cut with the housing held straight, or curved into its final position on the bike. The curves I believe would cause all the parallel wires in the housing to shift relative to each other (which is what makes it compressionless) so the ends of the strands might not all lie in the same plane if you cut first then bend. Maybe it doesn't matter.

xg5a

That's the correct procedure for cutting compressionless shift housing, right? I guess the question is whether or not the parallel wires inside the housing can slide along the length like in shift housing.

xg5a

Well, today I ran into a problem with setting up the brakes...

I discovered that Jagwire doesn't give you enough brake housing in this kit to run full length housings. That stinks!!!!! The 1700mm long brake cable housing section they gave me is only long enough to set up 1 brake. And what's worse, I can't find the brake cable housing for sale separately anywhere in the "Ergon green" color that I'm using. Does anybody know of a source where I can get such a housing? All I need is one more of the cable piece they sell with the kit.