Ask a Mechanic: Internal Cable Routing

Welcome to our Ask a Mechanic column where our expert mechanic Daniel Slusser answers your bike maintenance questions. If you have a question for Daniel, please post it on our Facebook Wall or e-mail Daniel directly at

Question: I have a new Cannondale SuperSix Evo 1 road bike and I want to upgrade the cable to a Gore Sealed system. This bike has internal cable routing for the rear brake. I’ve done some research on the Internet and it looks like it is really difficult to replace this cable. Any tips on how to do this? From: Jack

Answer: Internal cable routing is the bane of most mechanics’ existence. It doesn’t have to be though. Bike companies could fully line the internal routes of their frames with tubing to guide the cable through. They don’t do this because it costs more, is heavier, and engineers often lack the mechanical experience to foresee these types of issues during the design and production of a bike frame.

Gore Ride-On Professional Brake Cable Kit Black

Gore’s Professional System Brake Cables uses compression-less housing for crisp, immediate brake response.

Nevertheless, there is an easy solution that can help immensely in situations like yours. Just add in the liner tubing that the thoughtless bike company did not. Take a stretch of liner tubing such as the liners included in the Gore Sealed kit, and place this over the inner wire before pulling the wire out of the frame. Even if you are not going to use a sealed cable system, you can use this trick as an installation aid. If that is the case, once you get the new inner wire through the tubing, remove the tubing from the frame.

Now some of you are probably asking yourself, “Where do I get this tubing if I am not using a sealed kit?” You actually already possess the tubing you need! Just use the plastic liner of an old section of derailleur housing. To get to it use a knife or a pair of pliers to crack the outer sheath near one end. Then use needle nose pliers to grab onto one of the housing wires and peel it back like you would a banana. Once you peel it all the way to the end it will open up just like a banana peel and you will be left with just the tubing inside.

If I wrote these instructions clearly, following them should result in thousands of fewer four-letter-words uttered in anger. My work here is done. Press on in confidence home mechanics!

Daniel Slusser is a professional bicycle mechanic with over ten years of experience. He holds a bachelor’s degree in business administration from HSU and a master’s degree in history from Cal Poly University. When he is not riding, wrenching, or writing he enjoys spending time with his wife and two children.