Trailside Repairs: How to Fix A Broken Chain

A broken chain is a surefire way to turn an epic ride into an epic hike. Fortunately, with the right tools, it is a quick and easy fix, getting you cranking again in no time. What to Carry The only tool needed for chain repair is a chain tool. Here is what I carry: Crank …

By Corey Maddocks
April 27, 2012 Last Updated: July 13, 2021

16 comments

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A broken chain is a surefire way to turn an epic ride into an epic hike. Fortunately, with the right tools, it is a quick and easy fix, getting you cranking again in no time.

What to Carry

The only tool needed for chain repair is a chain tool. Here is what I carry:

Crank Bros Multi 17, with chain tool
SRAM Power Linkor KMC Missing Link
(they come in 8, 9, or 10 speed models. Make sure to get the right one)

Unlike some issues, a broken chain is immediate and obvious. Depending on what you were doing when it snapped, it may fall off into the dirt, wrap around the bottom bracket, or most likely, just hang in place. Either way, get off the trail and find a clean place to work in case any small parts get dropped during the repair.

ONOZ! I broke my chain!

Repairing the Chain

The first step is to remove the broken link. This is where the chain tool is needed. The tool will have a recess shaped for laying the chain link in, holding the chain firmly while the screw plunger presses the pin out. This step can be performed with the chain still on the bike, or it can be pulled off and laid flat.

(Click the pics for a close-up view)

Remove the broken link such that you are left with the ‘inner’ link of the chain on both ends. Like this:

The chain is now ready for the Powerlink. Insert each half into one end of the chain, from opposite sides, so that the pins and plates will interlock:

All that’s left is to snap the power link together. Look closely at the two link plates and you will see a slightly oversized opening on each one. Push the pins through those slots and then yank the chain. Done!

Of course if you removed the chain entirely, you’ll want to route it through the derailleur and around the cassette before joining the power link. The photo to the left is areferencepic of the path the chain takes through the rear derailleur.

Basically when the chain comes down off the back of the cassette, it goes over and in front of the top idler pulley, and then behind and under the bottom one.

With your chain repaired and back in place, pick up the loose links you removed, make sure to grab your multi-tool, and resume your ride!

Also, if a chain breaks out on the trail, it’s generally a good idea to replace it as soon as possible, making sure to keep your power link for future emergency use.

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16 Comments

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DanK_NoCo Colorado // 2010
Apr 28, 2012

>10 years ago a buddy broke his chain at the far end of the ride. Nobody had a chain tool, much less a power link. We managed to push a pin out of the chain with a little screwdriver and a stick, used like a hammer. To reassemble, we stacked a flat rock, the chain, the pin, and the flat side of a little wrench, and whacked this stack with a rock. We got the pin to go in, and it _only_ took something like 25 tries. Buddy rode the shortened chain back to the trailhead in SS mode. He did it without stopping for fear that anything but even pressure on the chain would improve the chance of it failing again. All three of us bought chain tools before riding the next day.

1 reply

AUTHOR

Corey Maddocks Colorado // 2008
Apr 27, 2012

@dgaddis, just don't go out with out a powerlink. Period. :D Seriously though, putting a chain back together on the trail without the power or quick link is sketchy at best, and is highly likely to break again.

@mtbgreg, my chain already has a powerlink out of the box, and I don't like riding with two. The final authority is a chain wear checker, but that's outside the scope of this article. In general, if it breaks once, it's ready to go. A really good KMC chain is like $50, with lower end Sram as cheap as $20, why chance it?

0 reply

@element22, no the solution to the pin problem is to carry a power link ;)

Syd Patricio Ontario // 2008
Apr 27, 2012

Depending on the chain, it may not be recommended to try and remove a link and reuse the pin. Sram recommends a powerlink/powerlock whenever a link is broken. Simply because when the pin tool pushes out the pin it rips a small retainer ridge that was part of the assembly process.. Shimano recommend using their replacement pins as well (rather than a powerlink) when it comes time to breaking a chain.

Pretty much what dgaddis said

Ever tried to find one of those Shimano pins in your pack when you eventually need it? :D

I should have mentioned, the Sram and KMC quick links work perfectly with Shimano chains.

I also heard a rumor that Shimano is going to go to a quick link too, but I haven't been able to confirm that.

Dustin Gaddis South Carolina // 2007
Apr 27, 2012

Good article. One I was planning on writing actually, but you beat me to it! The last two races I've done I've spent time helping people fix a broken chain. One tip - if you twist some links and have to remove a section of chain, don't forget that the chain is shorter now, and may not be long enough to work will all gear combinations. Stay out of the big ring.

arizonaglider 2011
Apr 28, 2012

Great article Madd. Because of you I always carried a power link for my Sram 27 gear chain. Since my new bike is a Sram 30 gear, which has a narrower chain, I'll need to buy a new link to carry in my repair kit. Love the bike maintenance articles, keep it up :-)

rcraft6826 2010
Apr 27, 2012

Great write up im sure this will help many people on the trail in the future!

RoadWarrior Texas // 2006
Apr 27, 2012

I have replacement pins, and powerlinks taped to my multi-tool

Greg Heil Colorado // 2008
Apr 27, 2012

If you break just one link and the rest of the chain is undamaged, I don't think there's a need to replace the chain immediately. A powerlink is designed to stay in place for the duration and function just as well as a normal link.

Great overview though!!

trek7k
Apr 27, 2012

Like you said, make sure you re-attach the chain AFTER you've routed it through both the front and rear derailleurs. On a group ride this week a guy snapped his chain, popped on a Powerlink, and realized he bypassed his front derailleur. For some reason he had a problem getting the Powerlink off (it was bent?) and spent 15 minutes cursing himself for not doing it right the first time. :)

Neither have I on the Shimano chain link. Solution to the pin problem is to place the pin along with other small but necessary spares in a plastic ziplock bag...

Oh, and if you don't have a power link you can always reassemble the chain yourself using the chain tool, just be careful when taking it apart not to push the pin completely out, leave it in one of the outter link plates. If you do this, the chain will be weaker at that link, modern multispeed chains aren't really made to be taken apart and reassembled. the pins are mushroomed on the ends to help hold them in place, but whe you push them out you undo that, so when reassembled it's not as strong as it was before. Pedal easy, and replace the chain ASAP.

bonkedagain 2007
Apr 27, 2012

When I replace a chain I usually stuff the old powerlink in my patch kit. I now have a bunch of spare powerlinks -- more than enough to share with somebody else who breaks their chain.

Fortunately, in all these years I've only broken a chain one time.

Bubblehead10MM Minnesota // 2012
Apr 28, 2012

Yah, I have the power link and tools, and some vague memory of fixing roler chains growing up on the farm. In other words no clue if I could still figure it out, so glad to have the primmer. Thanks. (and I'll try the zip lock thing. spare link has been in the little pocket in seat bag. but there's room in my tool kit to. need more)

You're right madd, it is highly likely to break again if reassembled without a powerlink. But, if you take it easy it could at least get you out of the woods without having to hike. At Snake #3 this year I helped my buddy fix his chain, he had chainsuck and twisted 5 different links, in 5 different places on the chain. Who carries 5 power links? Only option was to remove the twisted links and piece the chain back together. It held for a few miles, but did eventually break and he had to do a little hiking. But he only had to hike a mile or two instead of nine, and if he had taken it easy (which he didn't) he wouldn't have had to hike at all.

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