Bicycle Cable How-To

Intro: Bicycle Cable How-To

During my last ride, my front derailer cable gave up on me and froze. I use this all the time on rides so I was thankful that it waited until we neared the end of our third day of riding. Here are the steps to change a cable on a bicycle. Each bike manufacture is going to be a little different, but these should provide you some guidance in general. Worst case you have to take your bike to a bike shop and pay for the repair, so go for it!

STEP 1: Replacement Cable

Locate the correct cable for your bike. Stores like Wal-Mart and KMart often times have universal cable kits which ended up working great for my particular bicycle.

STEP 2: Cable Path

Before removing the old cable, take note of the path of the old cable. After a cable is out it might be difficult to determine the correct path when threading the new cable.

STEP 3: Remove Old

Ok, now that we have a clear picture of the path of the old cable, it is time to remove the old cable. If the cable runs through any of the bike's tubing, you may want to consider connecting a string to one end so you can pull the new cable through a difficult area. This was not necessary on my bicycle, but could be an issue on yours.

STEP 4: Compare

Once the old cable is off, lay the old cable and new cable side-by-side to compare for differences. If it is not the precise cable you may need to cut the cable to length*. I recommend cutting the cable a bit longer than the old one just in case. "Measure twice, cut once" is a good motto. If you end up cutting the cable, fit the cut end of the new cable with metal end that comes with kit. This is what the cable pushes against and without it your new cable will fail prematurely.

STEP 5: Thread New Cable

Thread the new cable along the path of the old cable.

**Sometimes it is easier or necessary to thread the outer cable housing separately first and then insert the inner cable once the housing is in place. Use your best judgment for your specific application.

STEP 6: Cable Length

Make any final adjustments to length.

STEP 7: Adjustment

If dealing with a gear cable, be sure to leave the control lever and the actuator in the proper relationship before clamping down the cable. I found that I had to make several adjustments before I had the cable where it should be for proper travel and control. Some bikes have threaded adjusters that allow you to fine tune cable / gear alignment after the cable is locked in place. In my case the real de-railer has this feature, but the front one does not so more care needs to be made when clamping down the cable on the front de-railer.

STEP 8: Final Adjustment

Take the opportunity to lube the derailer so the new cable works effortlessly. Crimp end on cable to keep cable from fraying. This can be done by pinching the small metal sleeve over end of cable and pinching with a pair of pliers.

STEP 9: Test Run

Take several test-runs before any major rides. Make sure your able to reach all the gears and that it behaves reliably when shifting gears.

Comments

[Phil B]

My bicycle maintenance manual suggests replacing shift cables after 5000 miles. I waited until 7000 miles before changing them. At 7000 miles they were so clean and good that I wondered why I was changing them. But, I have a road bike and my cables operate under fairly clean conditions. I am assuming yours is a mountain bike and it gets dirty in use. How many miles did you have on your cable when it failed, if you know? You might also be interested in a recent Instructable I did on Curing Bicycle Cluster Clatter.

[Ole-Grizzly]

You want to replace your cables before you think need to. Even without visible corrosion, they are stretching and breaking down on the microscopic level. Eventually a strand will fail and then they fail exponentially quicker one by one. Sometimes they stretch and weaken and then fail cataclysmic-ly. Shifting up for sprint for the finish line on the last KM of a race you've trained all year for. Or slamming on your brakes flying downhill as a car pulls out of a driveway without warning. Braking = good. Breaking = horrible

[edjsmith]

Hi Phil, My bike had set in the garage more than it was used so the cable froze more due to not being used than miles. I did see your Curing Bicycle Cluster Clatter. Great job! I've always liked the policy if it isn't broke don't fix it, but then that can bite you because you can have a breakdown out on a ride. Ed

[Phil B]

I could not tell the condition of my shift cables until I had them apart. By then it was as easy to install the new cables as it would have been to put the old ones back in. Since I was already past the recommended life of the old cables, I decided the new cables were the best course. I had read too many pieces of advise on what to do to limp home if a shift cable breaks out on the road. Thanks for looking at my Instructable and for your favorable comment.

[Ole-Grizzly]

never never WD-40 a bicycle. It was actually developed as a solvent and DE-GREASER for rust prevention on missile parts. It has trace elements of lubrication but it's far to light for bike parts. It forces out existing lubrication (with both it's de-greasers and it's pressure when applied. Leaving your bike running metal on metal. It appears to run smoother because it gets rid of dirt and grime (de greases...) but all lubrication vanishes quickly. BAD BAD news to use on a bike. I'm actually going to politely ask you to remove this picture to deter others from thinking it's okay to use it. It should only be used as a very very light lubricant on household objects like hinges or locks or toys. Never for heavy fast moving applications.

[mczagany]

Wow... no wd-40 on a bike there. All bout the oil.