Don't Chain-ge your plans: How to fix a broken chain

Fixing your chain on the road isn’t hard to learn and can really save a ride for yourself or a friend. Many multitools have chain breakers built in, but not everyone actually knows how to use them, especially on the side of the road.

While breaking a chain is nowhere near as common as getting a flat, it is a complete ride-ender if it happens and can leave you stranded in the middle of nowhere. The most common time I see a chain snap is from shifting gears under too much pressure. Whether it’s poor timing or just an accidental double shift, it happens to the best of us. If you or a friend does snap your chain, don’t worry—it can be repaired, even without any spare parts, as long as you have a chain breaker.

Chains are comprised of inner and outer links connected with rollers and pins. A chain breaker tool is designed to push out the pin to separate the links. There are many brands of chain breakers but they all work on the same principles.

First, I’ll cover what to do if you don’t have a spare quick link with you. There’s a temporary repair method that will get you home in a pinch, but it should be permanently repaired as soon as you get home. To do this, you need to find the first undamaged outer link. Then take your chain breaker and slowly start to push the pin out. You want to push the pin out far enough to remove the inner link, but not all the way—leave it partially in so you can reinstall it. Go slow and pay close attention, because if you push the pin all the way out, it can be very difficult (if not impossible) to get it back in.

Next, make sure you have an undamaged inner link on the other side of the break. Many times, when a chain breaks, it’s just the outer link that’s damaged—but always double-check.

Now it’s time to rejoin the chain. Put the outer link in your chain breaker with the pin facing the pusher part of the tool. Then line up the inner link and slowly push the pin back into place. Once it looks like it’s in the correct position, check that the link bends freely where you made the repair. If you pushed the pin too far—or not far enough—the link might be stiff.

There are two reasons this repair isn’t permanent. First, the pins aren’t designed to be reused like this. Second, your chain is now one or more links shorter. This repair should get you home, but be mindful of your gear choices—your chain is now too short for some gear combos. Avoid ones you should be avoiding anyway, like big chainring + big cassette. Once you’re home, replace the chain or at least cut out the temporary repair and add enough links back for proper length.

Be careful when applying heavy power and avoid cross chaining to avoid breaking this temp repair

The next method is better for a roadside fix and the same method you’d use at home to turn your temporary repair into a permanent one. This involves cutting out all the damaged links completely and restoring the chain to proper length.

If you’re lucky after your unlucky chain break, you may just need to cut out a damaged outer link and replace it with a quick link. After removing the damaged link, you should have two inner links, one on each end. Then install the quick link and apply tension to lock it in. In a shop, you’d use link pliers, but on the side of the road you can place the quick link on the top side of the chain rotation, just before it enters the front chainring, and give the pedal a little kick to snap it into place.

A quick link not fully set

If you’ve also damaged an inner link, you’ll need to cut that out as well. This will leave you with at least 1 outer link, which won’t work with a quick link. In that case, you need to keep cutting back until you’re left with two inner links again. While you could just install a quick link here and ride on, your chain will now be short. This kind of repair is solid for a weekend club ride, but if you’re doing an ultra or bikepacking trip, it’s worth doing a proper fix. That means carrying a small section of spare chain and an extra quick link(2x total). I like to keep the leftover links after cutting a new chain just for this reason. The procedure is the same as before—just now with two quick links and a new section of chain.

Fixing a chain is a valuable skill and easy to learn. Whenever you get a new chain, take the opportunity to practice pushing a pin partially out and reinstalling it on your old chain before tossing it. Carrying a quick link can save the day, but with all the different drivetrains out there now, if its not your chain that breaks, it may not be the right one. Quick links differ by speed and now manufacturer, especially with 12- and 13-speed systems so make sure you are using the right one for the specific chain.

Knowing how to fix a broken chain can make you the hero of the group and get everyone home, but hopefully you will never need to do it!