Bicycles Stack Exchange is a question and answer site for people who build and repair bicycles, people who train cycling, or commute on bicycles. It only takes a minute to sign up.
Sign up to join this community
I need to cut a cable, cleanly enough that it can be inserted in its housing.
What kind of cutting tool do I need for this?
I probably won't be using it more than once every few years, so cheaper options are preferred.
Also, tips to make sure the cable does not get disorganized when cutting would be appreciated.
Note: This question is not about cutting the housing.
You need a cable cutter. All of the companies that make tools for bikes make them. Here are a few options:
http://www.parktool.com/product/professional-cable-and-housing-cutter-cn-10 http://pedros.com/products/tools/brakes-and-shifting/cable-cutter/ http://www.performancebike.com/bikes/Product_10052_10551_1030380_-1___400625
As some of the other answers/comments have pointed out, it's a good idea to stick an awl (I use a fine-point nail set for finishing nails) in to the cut end of the housing after the fact to clean it up.
For the inner cable, the cable cutters will cut it cleanly with no prep or clean-up needed. If you're going to use a pair of regular wire cutters, then you'll want to use the solder trick mentioned in other answers.
That being said, you really should replace the housing when you replace the inner cable. It's rare for the cable to be worn to the point of needing replacement without the housing also needing to be replaced.
Alternately, you can use a Dremel tool with the cut-off wheel. Some people swear by this approach:
I'm naughty - I use a normal set of 6" side cutters on the inners and outers.
On the inners, I use a soldering iron and flux to heat and lightly tin the area where I will cut, then I simply cut it. The solder holds all the strands together, and also makes threading easier.
For the outers, I use a super-screw (self-tapping wood screw with a very sharp point) as an awl to poke in the end and enlarge the inner hole. Then I use a file to flatten off the end, turned so I'm filing metal on the far side, to reduce dust going down inside the inner. Finally I pop on a ferrule and its ready to fit to the bike.
Better tools would make this faster and cleaner, but for the once-a-year job its workable.
KevinC has the right answer - use either a dedicated set of cable cutting pliers from a bike manufacturer (don't use regular pliers or regular cable cutters, they will crush the housing) or use a dremel tool.
If using a cable cutting tool, make sure to either use a deburring tool to remove the sharp edges. Most tools have a deburrer built-in. With brake cables, you want to make sure you try to cut as cleanly against the helix at a single point (try practicing different small angles). With derailleur cables, the strands run perpendicular, so you want to cut at a perpendicular angle.
The OP has clarified that s/he isn't talking about the housing but the inner cable:
If you're using a dremel tool, it's helpful to wrap some electrical or other tape around the cable before you cut. This helps prevent the strands from untangling. Work in small cuts so you don't overheat the metal and start melting the teflon coating too much. Melted teflon gas is harmful so give yourself good ventilation.
My improvised techniques for when nothing else is around: using end cutters / carpenter's pincers :-) It can work pretty ok for some types of cables, but needs a bit of practice.
Cutting inner cables. For the simple (not teflon coated) inner cables, I never had issues cutting them with sharp pincers or regular cable cutters (though some of these are damaged by steel wires over time …). The individual steel wires will spread out along the cutting edge a bit when cutting, but I would twist them back into shape and there would be no permanent damage.
Cutting housings. If you have the type made with spiral-wound rectangular-cross-section wire, this can also be cut with sharp pincers. You bend the housing a bit so that, when going down, one cutting edge slides in between two spiral windings and cuts the spiral-wound wire instead of crushing the whole thing.
Hi I used a Dremel and it cut through the cable housing very nice but unfortunately the housing was lined with a plastic a tube and it melted it shut. After poking at for an hour or I went out and bought a cable cutter designed to cut cable housing. The moral of the story is check your cable housing before cutting.
Personally, I don't cut the cables, ever. Most cables are soldered at the end to keep them from fraying and even if they aren't, a drop of super glue can perform the same function. After threading the cable through the housing, just coil up the remaining bit, looping the cable around the coil at the same time to keep its shape, similar to the picture below, but in a much smaller diameter circle, and much tidier.
Why do it this way? No tools required, of course. But it also has the added benefits of always having full cables as backup in case one breaks. For example, if your rear derailleur cable snaps during a long ride, it would be better to replace it with the front derailleur cable (it's full length, remember) and adjust the stops on the front so that the chain stays on the chain ring you prefer. Then you'll at least have a range of gears rather than just a few chain rings to get you back.
