DIY bike workshop: Replacing internally routed gear cable housing with ease

There are countless ways to change an internally routed cable. And the aftermarket is full of special tools designed to make this time-consuming operation easier. In this article, we show you a smart way of replacing an outer cable housing for the rear derailleur. Without any special tools.

1 Release shift cable

In the first step, shift to the smallest sprocket of the cassette and loosen the fixing screw of the shift cable. Cut off the end cap (if present) with a cable cutter.

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2 Disconnect and secure the shift cable

Now pull the derailleur cable out of the rear derailleur at the entry eyelet. This is one of the most important steps: Secure the derailleur cable immediately. To do this, fix it as firmly as possible to the seat stay using adhesive tape. Important: Only secure the shift cable, not the outer casing.

3 Release cable ties and outer cover

If the cable does not disappear directly into the frame, cut all the cable ties holding the cover. Also check the transition from the rear triangle to the main frame.

4 Cut the front shift cable

To the front: Pull the outer casing a few centimetres out of the shift lever and cut the shift cable.

5 Remove the outer cover

Now gently pull on the front of the outer casing. Important: Only the outer casing should come out. The shift cable remains fixed at the rear and in the frame. It serves as a guide to pull in the new outer casing later. Pull the outer casing completely out of the frame and remove it.

6 Cut new outer casing to length

Cut the outer cover to the correct length. Use the old cover as a guide. Better too long than too short! Do not use side cutters for shortening, but a special Bowden cable cutter so that the cut is clean and nothing frays.

7 Slide on new outer cover

Next, the new outer casing can be threaded over the old shift cable on the head tube. Be careful not to push the shift cable into the inside of the frame. When the new outer casing protrudes a good way out of the frame at the rear triangle, the old shift cable can be pulled out.

8 Insert new shift cable

Remove the rest of the old shift cable from the shift lever. Depending on the model, the shifter may need to be unscrewed and opened. The new shift cable can then be inserted into the shift lever unit. Check the operating instructions if necessary. Screw the adjustment screw for the cable tension all the way in and then back out again by one turn. This leaves room for fine adjustment of the cable tension.

9 Thread on a new shift cable

Now insert the new shift cable into the outer casing. Do not forget the end cap for the outer casing at the upper end. Before the derailleur cable is threaded into the rear derailleur, the end cap must also be attached to the outer casing at the rear.

10 Thread in and tighten the cable

Once the rear end cap is in place, the derailleur cable can be threaded into the rear derailleur to the fixing screw. Depending on the model, this can be somewhat complicated - be sure to follow the specified guide. Then insert the outer casing into the shift lever and rear derailleur as far as it will go.

If the shift cable is inserted correctly, it is attached to the clamping screw of the rear derailleur under slight (!) tension.

11 Fixing the end cap

Now neatly cut off the protruding end of the shift cable with cable shears and attach an end cap. The derailleur can then be readjusted or fine-tuned. We have summarised how this works in this article.