Bike Hacks: Inside Guide

Internal cable routing has gotten much better since someone realized you could embed a tube in the wall of a carbon frame. But for some reason, not every brand does it. And not every frame is carbon. So, replacing your cable housing is often something akin to laparoscopic surgery.

But if you've already got a cable installed, the path is already laid. After disconnecting the cable, cut it just above where it was clamped into the derailleur so it's smooth from top to bottom. Instead of pulling the cable out of the housing, slide the housing of the cable, leaving it routed through the frame. Remove any reducers, guides or tiny little doors that may surround the ports where the cable enters and exits. Then, after cutting the new housing to length, slide it up the old cable from bottom to top. Before the new housing disappears into the frame, insert as much cable as possible. As you're sliding the housing up through the frame guide the old cable out at the same rate. No faster so that it's not pulling out of the housing, and no slower so that it's not bunching up.

Eventually, you'll be able to see the housing approach the exit. The old cable should be able to guide it out into the world. Once you've got it through, pull the old cable out, re-install the cable port hardware and slide your new cable through.