BROOKLINEBIKER

Hi everybody,
I am looking to replace the brake cables on my road bike. I have read that it is a good idea to use a scribe or awl to open up the cable housing after it is cut. I have also read that a metal file is helpful too for taking burrs off of the cable. Can anyone recommend a particular size or model for these items?

Malemute_Kid

For taking off the burrs, a Dremel rotary tool with the cutoff wheel works great, and is faster than a file.

wschruba

Scribes/awls, by definition, are tapered. The size doesn't matter (other than generally speaking. buy it in person). But you would want to buy an Awl, anyway, as it will be more comfortable to use.

Don't file the cable, you would file the housing end perpendicular, after cutting with side cutters. Make sure to cut along the bias of the housing (usually visible through the vinyl) for the cleanest, easiest to prepare end. If you are using compressionless housing, you will need to use a wire rope (cable) cutter.

*edit*

If you are going to use a dremel, use it to cut clean through, don't use an emery (or even a reinforced) cutting disk to dress something...that's a good way to shatter it. Use a sanding drum or grinding stone attachment.

BROOKLINEBIKER

Thanks, what do you mean by the "bias" of the housing?

Andrew R Stewart 

Bias in this case means to cut across the spiral to minimize the resulting burr. Cutting more parallel to the spiral tends to deform the end heavily. When just starting the casing cut you can feel the cutter blades (I use diagonal cutters)slip between the sprials. After the cut I open the inner liner with a sharpened spoke (at work. At home I have proper scribes) then square up the casing end (and remove any burr too) with a bench grinder. If you use a bench grinder be aware that the spiral will heat up a lot and can distort the outer casing plastic so pressing a ferule end cap can be hard. Andy.

wschruba

This, pretty much.

I assume that you don't have a bench grinder or a rotary tool, since you don't have an awl, so...buy a fine (as opposed to course) single-bastard mill file. Nicholson seems to be a popular brand in big box stores, though there are much better ones out there. Wear a glove on the hand holding the housing, as a new file will produce a very painful wound if you slip. Single bastard files only cut pushing, so don't drag it backwards, or you'll dull the teeth.

BikingZombie

Or just cut it and cap it. You can pick & file it, or not. I haven't, and that might put me in some ghetto class of those that take care of their bikes, but as long as you have a good pair of clippers I don't think you need to doctor the end with a pick and file.

Andrew R Stewart 

BZ- You're right in that not sweating the details is really needed. But those little things do add up and as a pro my customers expect it. I will say that if reusing inner cables that have been previously cut and not poking open the inner casing liner can cause the inner cable's raw end to fray open as it's fed through. That's a real hassle at best. Andy.

Ronsonic 

Or, as I managed to do once, the cutting wheel grabs the strands of the compressionless housing wraps them around itself and yanks the dremel out of your hand and creates an enormous snarl of broken wheel, tangled strands and liner with a delightful garnish of vinyl.

Andrew R Stewart 

Let me tell you about sticking my arm in a still spinning washing machine sometime... Andy

Vipon

i use a sharpened spoke as the awl

Looigi

Yeah. A sharpened spoke works, or any other cylindrical metal object (e.g. nail) that you can file to a nice point. Often you can clean up a jagged cut with stout diagonal cutters, which I find work better than cable cutters for cutting spiral housing. A fine tooth file is good but I use a Dremmel or grinding wheel if I deem the cut to be insufficiently clean. The issue with the latter two is that they can quickly generate enough heat to melt the plastic sheath and lining, which is OK if you successfully open the housing and, if needed, trim off any melted sheath.

fietsbob

in hand files in the same specific cut model is finer on a short file than a long one

Overlapping V and U jawed Housing and cable cutters cut from all sides At once ,

so are better that straight nippers like diagonal cutting ones.

dsbrantjr

My Felco cutters have V-shaped blades but they still leave the housing out-of-round. I take the time to file the end flat, and round out the inside with an ice pick. It takes maybe 15 seconds per end. I pop on a ferrule and the job is done right.

BROOKLINEBIKER

Thanks everyone, this is great information. Can anyone point me to a video showing filing of the brake cables? (I would like to have a visual model to look at it when I swap out the cables.)

HillRider

Cable cutters do a fine job for cutting inner wires and straight (or nearly straight) inner wire shift housing. They aren't so good for spiral wound brake housing and, like Andrew, I use side cutter pliers and work the edge between adjacent coils. I still have to clean up the small burr with a file and open the liner with a pointed awl.

woodcraft

Cutting and Sizing Cable Housing - Park Tool

big chainring 

Ditto. Good cutters make good cuts. I never even thought of filing the ends of cable housing. Cut and install. If I make a bad cut, just trim the burr. Any good cutters are capable of that.