important: Nuts and bolts on your bike should always be tightened to the manufacturer's specifications.

How to Replace an Inner Shift Cable

Remove the old inner shift wire and install a new one.

Shift cable inner wires wear out over time. Other than obvious fraying, rust or visual wear, you can tell your cables are worn when your shifting starts to feel sluggish. If lubricating the housings or shift levers doesn’t help, they’ll likely need replacing.

Tools

For this job, you’ll need a replacement shift cable inner wire. Shift cable ends have a cylinder barrel shape as shown here. I recommend stainless steel cables if you’re riding regularly in a wet climate, as they won’t rust. You’ll need a good set of wire cutters, some bicycle specific cable cutters if you’ll be replacing the outer cable housing, and some triflow or light lubricant. You’ll need either a 9 or 10mm metric open end wrench or a 5 or 6mm hex key for the derailleur’s cable pinch bolt. You’ll also need to know how to adjust your front or rear derailleur, as explained in previous tutorials.

Shift Cable Removal

The first step is to relieve cable tension by shifting your derailleur so the chain is on the smallest sprocket on either your front or rear derailleur.

Carefully observe how your cable is presently routed from the shift lever to your derailleur. A misrouted cable can cause many problems. It may help to photograph each section of the cable from the shifter to the derailleur so you can use it for reference. Your derailleur may not look exactly like the one pictured here, but the concepts will be the same.

Now disconnect the cable at the derailleur’s pinch bolt. Notice how the cable is flattened where it was pinched. I like to cut the cable just before this part so it is easier to remove by sliding through the outer cable housings. I recommend replacing the outer cable housings at the same time. See the tutorial titled “How to Replace Cable Housings”.

Shift Cable Installation

Once you have nothing but the shift lever and the cable left, push the cable gently until you see the head poke out of the lever. Now you can pull it the rest of the way until it is completely removed. Depending on what type of shifters you have, reinserting the new cable can be tricky. I like to give the end of the cable a slight bend to help guide it through. If it meets resistance, try rotating the cable a little bit and gently pushing until it slides all the way through.

If your shifter has a barrel adjuster, turn it clockwise all the way and then back it off one full turn. Drop some light oil into your cable housings and make sure the outer housing’s cable ferrules are firmly in place before carefully sliding the new cable through the housing. If your derailleur has a barrel adjuster, tighten it all the way clockwise and then back it off one full turn. Then route your cable the same way it was before and thread the inner cable under the derailleur’s pinch bolt washer. Often there is a groove on the derailleur where the cable is meant to sit. Pull the cable tight and tighten the pinch bolt. The cable will flatten when tightened. Always tighten bolts to the manufacturer’s torque specifications. Adjust the derailleur as needed. See the related tutorials for tips on adjusting derailleurs.

Once installed and adjusted, cut the wire about 2 inches further along the cable. Your new cable should have come with a cable end that can be gently crimped on using wire cutters or pliers. This will prevent fraying.

Alex Ramon

A bicycle geek since early childhood, spent his twenties as a mechanic in bike shops. His passions include flatland BMX, unicycles, cycle touring, mountain biking and road riding.

Related Tools

Discuss this topic in the Bicycle Repairs and Mechanics Forums

Oil can spouts

Lastest post 1 day ago

Years ago, oil cans had long spouts. Even the throw away cans had long spouts, but makers started putting little nubby spouts on the cans which makes it hard to get into some places such as my bike derailleurs. To oil those I have to pour oil onto a screwdriver blade and let it run down. The cans of '3 in 1' oil I used as a kid, on my bike, had a long spout. So after digging around I found cans w...

XT M8000 shifter spring

Lastest post 4 days ago

Hi, I messed up the tension spring for one of my MTB's shifters (Shimano Deore XT M8000) and now it's slightly yet noticeably bent on the tip. Is it actually worth spending my time to "straighten" it back and use it again? Or is it better just to get new one? Found some options on Ebay, such as this one, must fit well....

Upgrading ‘18 Trek Marlin 7 BB and Crankset

Lastest post 7 days ago

Currently running the OEM square taper BB with 3x9 but they’ve started creaking no matter how much I tighten the cranks. I think the damage is done and was wondering if there are other BB/crankset options out there besides square taper? Any recommended sizes? Thanks!...

Shimano M520 screwed the wrong way?

Lastest post 1 week ago

Randomly remembered about my first experience with clip pedals. Few years ago I bought my first Shimano MTB pedals (most likely M520, can't confirm it 100%), screwed them in and went on my training rides to prepare for mountain bike marathon. One training, after multiple rides, the pedal just broke loose on the way home (luckily not in the middle). Back at home I inspected the situation and found ...

Rim brake pads wear

Lastest post 1 week ago

Ciao. How can you tell that the rim brake pads are worn out and you need to change them? Or when is the right time to replace these brake pads?...

Can someone help me with price advice?

Lastest post 1 week ago

Hello, I just got this bike. I paid 50 bucks which I thought was fair. It is a Giant Acapulco probably from the late 90s/early 2000s. The bike functioned well until today when I felt the pedal wobbling and the pedal fell off. So I was reading a few other forums and they said that the crank arm was most likely the problem. The nut also appears to be stripped. So my question is should I just go to a...

Automatic bicycle chain keeps jumping off back gear

Lastest post 2 weeks ago

I have a 6speed autobike classic. the problem is when i stop and start to pedal again the chain slips behind the gears. when I'm going downhill or fast it changes properly but otherwise won't stay on the gears what can i do to fix this? Please help enclosed is a pic...

Is this a head tube carbon crack? Thanks for your help!

Lastest post 2 weeks ago

Hi, guys, the frame is 2017 Giant TCR ADV SL, can you tell this is a paint crack or a carbon crack? If it is carbon, repairable? Worth to repair? Thanks. 4F2F7C4D-0DD6-4271-A1F8-47D66B037913.jpeg (Size: 293.65 KB / Downloads: 3) 5D9E939D-05B9-4691-8586-8D33F305A7E2.jpeg (Size: 228.73 KB / Downloads: 3) ...

Mollema about SRAM mechanical

Lastest post 2 weeks ago

Hahaha, took a break from project writing tonight and found this video on youtube from Giro d Italia: Bauke Mollema: "F**king SRAM" (volume UP!) Made my day/night ...

Bike changing gears random

Lastest post 2 weeks ago

I was biking home with my college friend and her chain was jumping at random changing gears on the back wheel from the smallest cog (is that how you call it?) to the second smallest. She has 7 speed on back and one chainring in front. She has been ignoring this chain jump for few weeks, but now it has become too annoying. Can we somehow fix it easily by ourselves? One guy said that the chain look...

driveside threads showing/bottoming out on 1980 tubular wheel

Lastest post 2 weeks ago

so got this peugeot hle of my dad, as good as unused(all cups mint) with araya tubulars 32ish 1,8mm alloy(rim brakes ofc). started working on em, allways got wobbly when releaving stress, kept truing/tensioning em, bang a spoke broke, i had twisted it off from the spoke bottoming out. looked around the wheel and almost all driveside spokes show loads of thread. how come?. i guess the wheels are s...

Creative bike mechanics (freehub)

Lastest post 2 weeks ago

Just wow, this calls for the bicycle repair photo of the month prize! As this bike rider himself explained, his friend's freehub turned fixie during the ride, and they used such creative tool to get the 16mm nut out of the hub. bottom-bracket-diy-tool.jpg (Size: 137.34 KB / Downloads: 38) ...

Ditch this rim?

Lastest post 3 weeks ago

Hello everyone. I was taking out an older bike from parents shed for potential refurbish. Noticed that its front wheel has small cracks around 3 of the spoke holes. They look like the one in this photo, distributed evenly around the rim. Those are cracks, not scratches. Is it safe to bike with such cracks or is it better to get new wheels? bike-rim-crack-3-spokes.jpeg (Size: 76.3...

Is my front wheel on backwards?

Lastest post 3 weeks ago

Hello, I was doing some maintenance on my road bike and I took the front wheel off, removed the quick release axle from the wheel, set the wheel aside, and put a drop of tri flow on the axle to lubricate it. When I returned to the wheel to reinstall the axle I knew the quick release goes on the left side of the bike's fork due to previous pictures I have taken of the bike. However, returning to...

Fender lights

Lastest post 3 weeks ago

As found on internet and should be shared; fender tail light modification: https://imgur.com/gallery/VdxLvp4 The end result provides better light performance + does not bother panniers/bike bags + theft resistant. Steps: - removing light clip - drilling recess for M5 bolt - spacing out with linear brake hardware - securing with washer & nut...