How to Fix a Broken Bicycle Chain on a Ride

Being Prepared to Fix Broken Chains on Rides

by Jim Langley With the technology that’s gone into modern drivetrains, you can argue that we have the strongest, best shifting chains ever and you should never worry about breaking one on a ride. But even if that’s true – every roadie should know that if you DO break a chain, it can mean the end of your ride. Because, without a working chain, you can’t pedal the bike.

That’s why I recommend and try to always carry the tools and key part to fix broken chains. It’s not just for me. I use my kit to help stranded riders who’ve broken their chains. And from that experience, I know that chains do still break. It’s not always the fault of the chain, either. Sometimes the chains were improperly installed at the factory that built the bicycle, leading to the failure. And, even on road rides (not just mountain biking), things can get caught in and mangle the chain beyond use.

To be prepared to fix broken chains, requires carrying a few small items as follows.

1. A mini-tool that includes a chain tool that allows driving a pin out of the chain (I carry an old version of Crank Brothers’ M17 tool) https://www.crankbrothers.com/collections/m-series/products/m17 or http://amzn.to/2FN003o
2. A chain “master link” of the same width as the chain you are repairing (i.e. 5, 6, 7, 8, 9, 10, 11speed) http://kmcchain.us/connectors-list/  10 speed Shimano
3. A tool to break free and remove the master link, such as Wolf Tooth’s Master Link Combo Pliers https://www.wolftoothcomponents.com/collections/tools/products/pack-pliers or http://amzn.to/2Fy6vb9

Note that even if your chain does not have a master link joining its ends (this is a relatively new feature), I tell everyone to carry a master link because it makes repairing breaks much easier and faster.

Fixing a Chain With a Broken Link

What’s needed to repair chains out on the road depends on how they failed. If you’re lucky, you will only break one link. In that case you need to remove the link that failed with the chain tool on your mini-tool. Then to fix the chain, you will simply install the master link with your fingers. KMC’s Missing Link is a popular choice, and other chain companies make them, too. If you’re running a top-line chain you may want to carry the specific master link made by that chain company for that specific chain.

No tools are required to install the master links, but some are directional, so be sure to read the directions. Or save the instructions in your seat bag with the link for referral when you finally need to use it.

Fixing a Chain That’s Bent and Twisted

A chain might get bent and twisted if a stick gets stuck in it, you don’t realize it, and you keep pedaling. If the links get bent badly, the chain will trip up running through the derailleurs and can damage them. So you want to fix the chain. To do so requires removing the damaged section of the chain.

For this on chains with master links, you may need to free and remove the master. A nice new tool for this is Wolf Tooth’s Master Link Combo Pliers ($29.95). They fold small, weigh only 38 grams and ingeniously hold 2 master links inside with a magnet so they won’t get lost. They also double as a tire lever and pliers to unscrew tight valve nuts and tighten valve cores, too.

The Combo Pliers make it easy to squeeze the master link together and unlock it so you can remove it from the chain by hand. Once out, you can use your chain tool on your mini-tool to drive a chain pin out in the right spot so that you can remove the damaged section of links. To finish the repair, you put back in the old master link if it wasn’t damaged. Or you put in a new one if the old one was bad. In some situations you may use need to use two master links.

Important: When you have to remove links to repair a chain, the chain ends up shorter than it was and that can mean that’s it’s too short to shift into the extreme gear ratios. You want to keep that in mind when riding home and not mistakenly shift up onto the larger cogs when you’re on your largest chainring. If not, you can get the chain stuck and have to remove the rear wheel in order to free it from that extreme position – or worse, possibly break the chain again.

With this small amount of preparation – and a little analysis on how best to fix problems, a broken chain should never ruin your ride again.

Bonus Tip: Since you might not think of this, I’ll finish with a way to get home if for some reason you can’t fix your chain (for example, maybe it broke, fell to the ground and you couldn’t find it by the time you stopped – don’t ask how I came up with this scenario). What you can do when you don’t have a chain is walk as necessary and coast as much as possible. If you’re riding with friends, someone can push you along. These things aren’t as good as riding, but they will get you to help in a pinch and are a lot faster than only walking your bike. And what fun is calling for someone to come drive you home?

Jim Langley is RBR’s Technical Editor. He has been a pro mechanic and cycling writer for more than 40 years. He’s the author of Your Home Bicycle Workshop in the RBR eBookstore. Check out his “cycling aficionado” website at http://www.jimlangley.net, his Q&A blog and updates at Twitter. Jim’s streak of consecutive cycling days has reached more than 8,000. Click to read Jim’s full bio.