How to replace a gear cable on a road bike

A new gear cable can reduce friction and improve shifting. Here’s how to change a gear cable on a road bike

Clock08:59, Tuesday 14th May 2024

Whether it be to improve shifting or replace frayed wires, you may need to occasionally change the gear cables on your road bike.

What may appear to be a tricky job is actually quite simple and in this guide we’ll take you through the process for replacing rear gear cables for Shimano-equipped bikes. The process is similar for replacing front derailleur cables.

In this example, we’ve used a bike with internally routed cables, and with outer cable housing. This housing runs through the entirety of the frame, making it easy to thread a new cable back through. Not all frames have this, so you may need to buy housing separately as this will make the job easier.

To complete the job, you’ll need spare cabling. Both Shimano and SRAM’s cables are interchangeable so either can be used, but Campagnolo’s is slightly different. Cabling is relatively cheap so we’d recommend investing in a higher quality cable as this will reduce friction and last a little bit longer.

You will also need a 4mm allen key, cable cutters, pliers and a pick or a screwdriver.

Need more maintenance help? From indexing gears to fixing punctures, explore all of GCN’s how to guides

Tools Needed

Step 1

Loosen the cable pinch bolt

Shift into the largest cog on your cassette and then use an allen key to loosen the pinch bolt located on the derailleur. This is the bolt that holds the end of the gear cable. It doesn't need to be completely loose, but just enough to remove the cable.

Top Tip

Use your pliers to remove the cable end crimp. If it pulls off in one piece, you will be able to reuse it on the replacement cabling.

Step 2

Find the cable in the shifting levers

Locate the correct gear lever and pull the rubber cover back from the brake hoods. This will unveil a little plastic cover on the inside of the hood. Use a pick or screwdriver to lift this, which will expose the cable.

Step 3

Remove the cabling from the frame

Use the same pick or screwdriver to pull the cabling slightly out from under the plastic cover. This will give you the leverage to pull the cabling out from its outer housing and the frame.

Step 4

Feed the cable out of the lever

Once it is out of the frame, the cable needs to be pulled through the lever from the opposite side of the hoods from the plastic cover.

Step 5

Insert new cable into shifter

Unravel your new cable and then feed it back through the outer hole on the shifter. There is a little divet in the hole for the cable end to slot into, so pull the cable fully through until this can slot into place.

Step 6

Feed the cable back through the frame

Now, feed the cable into the outer cable housing and through the frame until it comes out the other end near the derailleur. Pull it through until the cable is taut with no snags. Double check that it is taut before continuing, as a slack cable will affect shifting performance.

Top Tip

If you experience friction or difficulty, try removing the end cap from the outer cable near the derailleur. Just remember to replace it once the cable has thread through.

Step 7

Attach the plastic cover on the shifter

Double check that the cable is tight around the shifter and the end is slotted in place. Then push the plastic cover back into place and push the rubber cover back over the hood.

Step 8

Prepare barrel adjuster

Wind the barrel adjuster fully clockwise. You will need to index your gears once the wire is installed and this will allow for a full range of adjustment, if needed.

Step 9

Slot the cable through the barrel adjuster and bolt

Slide the cable through the barrel adjuster, making sure the outer cable securely slots into the adjuster, and then through the pinch bolt.

Step 10

Secure the cable using the pinch bolt

Use your free hand to create some tension in the cable and then use the allen key to tighten the pinch bolt. Follow any recommended torque limits when tightening this.

Step 11

Trim the cable

If there is lots of excess cable near the derailleur, it will need trimming down. Don’t cut it too short. Try to leave a couple of inches of loose cable, so you have further scope for adjustments in the future if needed.

Finish by attaching the cable crimp, using pliers to secure it in place.

Step 12

Index the gears

Now it’s time to index the gears. If the limit screws were already set up correctly, these shouldn’t need adjusting, and it should just be the barrel adjuster.

To set the cable tension, move to the smallest cog then shift one gear up. If the chain chatters but doesn’t move, turn the barrel adjuster counter-clockwise until it does. Continue this step throughout the cogs until the chain is shifting smoothly across all of the gears.

Jargon Buster

GCN's Essential Road Bike Maintenance
GCN's Essential Road Bike Maintenance

For road, gravel, commuter and hybrid bikes, Essential Road Bike Maintenance is intended to be a proper bible to all those essential bike maintenance, repairs, and set-up tasks that we all need to know. Everything from basic bike set-up, how to get your wheels on and off, through setting up gears, bleeding brakes, and beyond to things like installing electronic gears, converting to a 1x transmission and more. In a nutshell, pretty much everything you would want to tackle on your bike (or bikes, plural) yourself. And then some. Like bike set up tips for taller and shorter riders; bottom bracket standards explained; common bike maintenance mistakes and how to avoid them; essential roadside fixes to keep you riding; how to make your bike more comfortable; how to puncture-proof your ride and much, much more. “A huge amount of knowledge, hacks, and know-how to help improve both your workshop skills and your ride” – Ollie Bridgewood, GCN Presenter Each chapter is structured with the tasks you’ll most likely need more of the time at the start (like how to adjust your gears, replacing brake pads, or changing a tyre), before running through to those that you’ll do much more infrequently (such as changing disc brake hoses, servicing a freehub or pedals, and so on). This also means that many of the tasks naturally ratchet up in difficulty as you go through each chapter which should also mirror your natural progression as you become more mechanically capable and confident. In short, 260 pages packed with all the essential knowledge you’ll need to confidently take on and complete pretty much any bike maintenance task. Get Some ‘Show-How’ With Your ‘Know-How’ Each walkthrough is linked to a companion video which you can watch for free from your computer, tablet or smartphone. To watch, either type in the walkthrough’s short-link URL – e.g. https://gcn.eu/GetPerfectShifting – into your browser, or scan the QR code with your smartphone or tablet so you can get the best of both worlds: know-how and show-how. Simple. All you need to know to fix your bike. Product Details: Pages: 260 (120sm) Size: 280mm (h) x 216mm (w) (portrait) Cover: Paperback Cover Finish: 300gsm, silk stock with anti-scuff matte laminate and spot UV gloss finish Please note: There may be some additional shipping charges for orders consisting of 2 or more books. However, our customer service team will contact you after you have placed the order to advise on delivery options. Click here to explore all GCN best selling books

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