Toolz of the Trade

Modern carbon bikes have gotten pretty slick looking with new aerodynamic shapes and fancy hidden or internal cable routing.

One question I get a lot at work is, "How do you get them cables through that there frame?" A lot of frames like the Focus Izalco have guides molded into the carbon, so there's really no challenge at all. But for the really fancy guys, like some of the Trek Madones, Guru TT bikes, and the Cervelo line you are really just sticking a wire into the darkness and hoping for the best.

There are a few special tools that we use over at Running Away Multisport to ease the process and the pictures below are labeled to explain what the tools do.

From left to right:
1. The twisty light is for peering into small holes. The other end is magnetized for sticking to things.
2. The hooked thing is a tooth scraper from a dentist's office. We have a couple different shapes for different jobs. You can make your own out of a sharpened spoke or piece of copper wire.
3. The cable grease is useful any time you need to feed cables through housing.
4. The two super magnets on the right are used to hold the cable in place through the frame. They can also be attached to the hook for added grabbing power.
Above:
Coffee, a pen and paper, and patience are just good things to have in general when working on bikes. 

As you can see, the access hole on this bike is tiny. On some models you can take out the bottom bracket and get at the innards, but on this one you just have to poke the cable through and use your tools to grab it.
Pro tip: sometimes I bend the end of the cable so it sinks into holes more easily. 

Good luck and try not to cross the front and rear derailleur cables inside the frame or you'll get inconsistent rear shifting. Don't be afraid to re-do your work if something doesn't seem right. The more you do it the better you get.