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I'm replacing all my cables right now and I'm just wondering if the initial cut of the brake housing (Jagwire in this particular case) should be cleaner than what's shown below. These pictures are right after cutting, before cleaning up the end.

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I'm using a Park Tool CN-10 housing cutter. When cutting, I line up the cutters at the target location, hold the handles as far back from the pivot point as I can while still maintaining control over them, and cut with one quick single squeeze. The resulting cuts usually still have a little burr of metal, sometimes obstructing the opening of the housing. If it's large enough, I'll use the cutters again to just snip the burr off. Then I file any remaining small burrs and use something small like a toothpick to flare the inner lining a bit.

Should the initial one-shot cut of brake housing come out cleaner than what's shown above? Or is that about as good as it gets with a tool like this?

Thanks.

SSilk
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    Looks about par. How cleanly it cuts depends on the chosen cutter, the skill of the mechanic, and the brand/style of the cable. – Daniel R Hicks Apr 23 '23 at 18:21
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    Looks normal to me and the way you are handling it (snipping of big burrs, filing it down, opening inner) is good. – Michael Apr 23 '23 at 20:21
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    Looks pretty normal to me. I found Shimano's cable cutters a little better (in this respect) than Park Tools'. Back when I was a full-time mechanic, I built a little hinged wooden jig to hold a die grinder with a cutting disc, so you could use it like a tiny chop saw. Gives really clean, square cuts--but probably only makes sense if you build high-end bikes all the time. – Jerry Coffin Apr 23 '23 at 23:33
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    I have used Dremel with a cutting disc just hand-held, it also gives pretty clean cuts even though you need to eyeball the squaredness. – jpa Apr 24 '23 at 09:02
  • I will note that a "bolt cutter" will usually produce a cleaner cut. – Daniel R Hicks Apr 24 '23 at 12:45

2 Answers2

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No that's about normal. The inner liner is mushed over to one side, this always needs fixing with a pointed probe.

The outer spiral winding looks rough, but remember you're cutting some springy steel at a steep diagonal. Four or five licks with a file will clean that up nicely.

I suspect the higher-quality jagwire cable has more thickness in the outer winding compared to cheaper cable.

As a test, grab an offcut of this same outer and try to cut it with other tools, like pliers and a hacksaw. I bet those cuts will be significantly worse.

Criggie
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    I run a small piece of cable in the housing end and then cut the housing. This helps to keep the housing shape and not smash down the inner liner when cutting. If I don’t like the cut, I’ll cut it again or use a Dremel cutting wheel to square it off. – P. Barney Apr 24 '23 at 15:10
  • @P.Barney I keep a drywall screw with my cable cutter. This is a convenient took for opening up the liner and giving it a slight bell-mouth. – Criggie Apr 24 '23 at 23:25
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I have never used the Park Tool, but I used the Unior and the Shimano. I can say that the Shimano housing cutter works better than the Unior.

Your technique is the one I also used and the result your are showing is not something very different that I usually see when cutting housings. Here is a picture of the first cut I made after seeing your post using the Shimano cable cutter on Shimano SLR brake housing (I usually use Jagwire, but I had a section of SLR lying around):

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I was surprised how this cut came very clean (liner is open and not much extra metal). Usually with Jagwire, it is less so. Another cut I made later on the SLR housing though needed the pick to open the liner and there was more metal to be removed. If there are too much metal to be removed like on your picture, I prefer using high quality diagonal cutting pliers rather than the housing cutter before filing.

So, some cuts are cleaner than others, but usually in my case they pretty much all need to be cleaned up to some extent. If we could always position the cutter and orient the metal spiral the same way as our cleanest cut, life would be good. It might be possible with some deliberate practice.

olliebulle
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