Internal Cable Routing – How and Why

June 3, 2013 Frame Building 0 Comments

But why internal cable routing in the first place? Well I love the look of simplicity and clean lines. Internal cable routing definitely brings that to the table! I also don’t like worrying about picking up my bike and scratching the paint when I grab the bare cables, or trying and failing to remember to grab the seat tube instead of the top tube. Sure it’s not a big deal, but it’s the little things that matter! The disadvantage is of course a bit of extra weight, but it’s such a nice detail and I never worried to much about weight anyway.

So, here we go! Here’s a mitered tube ready to go, and a 7mm brass tube for the internal routing, which will fit the standard fatter brake cable housing. A smaller diameter can be used for shifter cable housing.

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First step is to drill a hole in one end of the tube. I think I used an 8mm bit here.

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Next we shape the hole by tilting the drill off axis, in the direction of being parallel to the main tube.

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Since the drill bit and the cable guide are the same shape, this gives us a pretty nice fit as you can see. Then we do this on the other end, and feed the guide from one end to the other.

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Here we are looking into the main tube, you can see the guide coming through. It needs to be bent a bit, and then as long as everything is ligned up it comes right out the other side.

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Now the guide is in place, and we are ready to braze.

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So we get to the fun part! Brazing is done with silver here, so that we don’t melt the brass. The main tube tends to heat up quicker, so keep most of your heat on the brass.

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Now we just cut the excess off with a hacksaw, being careful not to cut into the main tube.

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A bit of work with the file cleans things up.

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A bit of sandpaper as well takes the sharp edges off.

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And the final result it quite beautiful, I think!

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Here it is in action, or at least a test run. Thanks for looking and hope you enjoyed this quick tutorial!

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