Is a wound cable too much for the "cable **and** housing cutter"?

Question

This is a sequel to an earlier question.

Park Tool's CN-10 (and similar, such as Pro's Team Cable Cutter, Jagwire's Pro Cable Crimper and Cutter, Pedro's Cable and Housing Cutter, Feedback Sports' Cable and Housing Cutter, Shimano's TL-CT12 Cable Cutter, and others), is labeled "cable and housing cutter".

But in Park Tool's own video Calvin Jones uses the side cutter pliers SP-7 for cutting (brakes) wound housing.

Is the (brakes-specific) wound housing too tough for the CN-10? I have enough extra cable length to experiment, but I'd rather not risk damaging the CN-10.

Will good hardware-store side cutting pliers (aka diagonal cutting pliers) do the trick, or is the SP-7 (or similar) really necessary?

Another experiment, as mentioned in an answer to the question quoted above, is to use a Dremel circular cutter. There I'm less worried about damaging something than having a circular cutting tool fly off into a body part (and I won't know whether I can do it fast enough to avoid heat that will melt the plastic parts until after the fact).

Answer 1

Tools like the CN-10 and other bike-specific cable and housing cutters are meant to do one thing that other cutting tools struggle with: cut compressionless housing (parallel or braided wires) cleanly without any crushing or other mangling. They do it by cutting into all sides simultaneously.

Compressionless housing cutters are also good at cleanly cutting brake and gear inner cables, but good quality side and diagonal cutters do that too.

They cut through spiral housing without issue, but they don't typically do it as cleanly as a good side or diagonal cutter with good technique behind it. They're not designed to make it easy to slip in between coils on a spiral housing and cut it without any crushing of the spiral form, which has to be cleaned up if it occurs. That's not to say they can't be used for the purpose, because many people do and it can still be cleaned up to a fine result, but they are not optimized for the purpose. Some are less bulky and prone to those issues than others (the Shimano ones are relatively slender for example).

Side and diagonal cutters (they're used somewhat interchangeably on bikes) are a tool that vary enormously in quality. A lot of bad ones are not capable of cutting spiral housing cleanly either because they're not hard, sharp, and/or gapless enough. Since a lot of people only have examples of this type around or that's all they've ever handled, it can lead to a murky conversation about what they're capable of categorically. The very best diagonal cutters in good, sharp condition actually do a good job on even compressionless housing (I've only seen Knipex ones do this), although they still crush the housing more than a cutter made for the purpose.

Answer 2

In various busy workshop environments I have personal experience of, the CN-10 is the preferred tool. It is an absolute animal and extremely durable. Wear can also be adjusted out.

You are right that is can occasionally deform the end of spiral brake housing. This is avoidable but if it does happen there are two approaches to cleaning it up quickly:

• Cleanest finish: Touch the cut end to a bench grinder for a very clean square finish. Takes a second or less (once the grinder has spun up). Does not melt plastic outer.
• No bench grinder: Use your CN-10 or other cutters to nip off the small bit of spiral that is reducing the cable aperture. It's easy enough to do and this is most commonly done when the "perfect finish" isn't required or the bench grinder is unavailable.

I don't see the need for a tool like the SP-7 in a workshop dealing with the majority of bicycles. I would rather invest in a good quality pair of scissors.

Answer 3

Just wanted to document what one can do with just the CN-10.

The cut on the left is the result of using the CN-10 once on the wound cable. In the second image on the right I used the same tool to cut only a portion of the helix, with the objective of exposing the interior plastic sheathing to make it more likely that (during handlebar turns or other cable movements) the interior plastic sheathing will be the one that will touch the cable, not the wound helical steel cable.