How to fix the bike chain

Along with a flat tyre, a broken bicycle chain is the most likely mechanical failure to leave you stranded by the roadside. Make sure you know how to repair a broken bicycle chain with this easy to follow repair guide from Simon Jackson of Cadence Performance.

How to fix the bike chain

A broken bicycle chain will render your bike useless but can be repaired on the road, at least sufficiently to allow you to ride home.

You will need a bicycle chain-tool which comes as part of most multi-tools, as well as a spare quick-link. It is perfectly okay, and in fact advisable, to leave the quick-link permanently fitted for the life of your chain. They can be difficult to remove by hand, so be mindful of this before connecting the chain.

Initially it will be necessary to remove any broken parts of the bicycle chain.  The method described below may render your chain a little shorter than usual, especially if the chain has twisted.  This can mean that the new chain length may not accommodate the larger sprockets on your bike. As a rule, therefore, it is advisable to stick to gear combinations using the smaller chainrings and sprockets if you chain ends up shorter.

How to repair a broken bicycle chain:

  1. If the chain has not already fallen off the bike then remove it.
  2. With the chain removed, change the gears so that the front and rear derailleur align with the smallest chainring at the front and the smallest sprocket at the rear.
  3. Identify the nature of the damage. Usually it will be that one of the pins has lost its hold on one of the outer plates of the chain. Less often the plate of the chain may have broken. You should also inspect the chainrings, sprockets and both derailleurs for bent teeth or misaligned parts.
  4. Remove the broken parts of the chain by pushing out the pins adjoining the damaged parts.

With the pin-driver withdrawn, place the chain onto the hooks in the chain-tool. The hooks hold the chain so that the pin lines up with the pin-driver. Turn the lever so that the pin-driver pushes on the pin. Initially this requires significant torque, but is much easier after this point. A chain-tool with a long handle makes this easier.

How to fix the bike chain

Figure a. Push out the pin with the chain tool.

In order to fit the quick-link you will need to end up with each end of the chain comprising of the inner plates. To achieve this it may be necessary to remove undamaged parts of the chain. Have a think about this before you push out any pins, which cannot be refitted, and remove only the minimum number of chain parts necessary.

How to fix the bike chain

Figure b. Chain ready for quick-link.

  1.  Rethread the chain through the gear parts. This can be fiddly and is best done with the bike in an upright position. Begin by threading one end of the chain through the cage of the front derailleur in the direction of the rear of the bike. Pass the chain over the smallest sprocket of the rear gears and then under the sprocket. The chain then should wrap around the top jockey wheel, to the front and the lower jockey wheel to it’s rear. Ensure that the broken bicycle chain is not rubbing on any part of the rear derailleur. When fitting the quick link it is best to leave the chain hanging behind the front chainring, to allow plenty of slack in the chain. If the instructions above are followed then the two ends of the chain will be positioned in the lower part of the chain.

How to fix the bike chain

Figure c. Diagram of the correctly fitted chain prior to being reconnected.

  1. Connect the two ends of the chain using the quick-link by following the steps below.

How to fix the bike chain

How to fix the bike chain

How to fix the bike chain

Figure d. This quick-link is not yet properly connected.

  1. To secure the quick link pull each end of the chain away from each other until it is extended to the full length of one chain link. If this cannot be done by hand, then place the chain on the front chainring and gently pedal backwards. When the quick-link has moved to the upper portion of the chain, then hold the rear brake and apply some downward force on the pedals. This will pull on the chain and engage the quick-link.

How to fix the bike chain

Figure e. The quick-link is securely connected.

  1. Once again ensure that each side of the quick-link is properly engaged. Fit the chain onto the chainring and test that it runs smoothly over the sprockets and chainrings before riding.

How to fix the bike chain

Figure f. Chain connected and fitted to the chainring.

Can’t fix your broken bicycle chain by the side of the road?

Sometimes we get mechanicals that we just can’t fix ourselves by the side of the road. Yellow Jersey Bicycle Insurance includes taxi reimbursement if you have a mechanical and cant get home. THis ‘break down recovery’ is available on the Performance and Ultimate tier policies.

MOre EXCELLENT cycling  tips blogs:

Cadence Performance are based in Crystal Palace. As well as offering top class repairs and servicing, you can join them for indoor cycling sessions, fitness testing, bike fitting and more. They are also a main dealer for award-winning Giant Bikes.

How to fix the bike chain

By Dan Goldwater

Expert Do-It-Yourselfer and Instructables.com co-founder Dan Goldwater has the hands-on solution for just about any bike project you can dream up. In this issue, he gets back to basics with the best approach to fixing a broken bike chain.

How does a chain work?

Each link of a chain is held together by a steel pin/ peg. With the chain tool (or a hammer and pliers) you can push out and push in the pins, allowing you to remove or attach links. Fixing a broken chain amounts to removing the broken link and re-attaching the remaining loose ends. On bikes with derailleurs, there are enough extra links that it’s no problem to remove a couple. On a single-speed bike, you probably won’t have enough slack in the chain to remove a link, you’ll need to borrow some

links from an old chain or else buy a new one.

How do chains break?

The most common way is by pedaling full force at the same moment that you are shifting your front derailleur. Other breaks I’ve seen were caused by an assortment of seemingly one-in-a-million occurrences, yet I’ve seen enough of those cases that I guess, if you ride long enough, one-in-a-million happens. Things like a nail getting thrown up by my front wheel and lodging in the chain, then getting cranked across the sprocket. Who’d a thunk?

Unless you do a lot of mountain biking, it isn’t often that you’ll need to repair or change your bike chain. However, chains do break now and then, and being able to fix one on the street is no harder than fixing a flat tire if you are prepared.

To fix a broken chain, all you need is a chain tool. These are compact and built into many common multi-tools, such as the one shown (Slideshow image a). You may even already have one on your multi-tool – now you know what it’s for! At home in your garage, it’s possible to repair a chain with just a hammer and pliers, but a chain tool is easier, and really the only option on the street.

If you are on the street and your chain breaks:

1. Are you wearing nice clothes that you care about? Probably best to lock your bike and take the bus. Come back later with your old jeans and fix it then. Fixing a chain is the dirtiest job there is on a bike.

2. Okay, you’re back and ready to go. Flip your bike over so you can get at the chain more easily.

3. Take a look at the two broken ends. You’ll need to remove two segments of the chain because the two types of segment alternate. If you just remove one segment, you can’t reattach it. Place the chain into the groove in the chain tool (Slideshow image b) at the spot you want to disconnect. If you are replacing a worn but non-broken chain, you’ll do the same thing here.

4. Turn the screw on the chain tool to start pushing the pin out of the chain (Slideshow image c). Be careful to keep the pin on the chain tool lined up with the pin on the chain; they sometimes like to slip around a bit.

5. Don’t push the pin all the way out! Only push it just far enough so that the chain comes apart (Slideshow image d). You need to leave the last bit of the pin in the chain so you can push it back in later.

6. Okay, now feed the chain back onto your sprockets. It helps a lot if you have a friend who can hold the two ends in position while you reattach them.

7. Now use the chain tool to push the pin back in (Slideshow image e). The trickiest part is to keep the tool lined up with the pin. Note: if you are putting on a new chain here, many new chains come with a special link that makes the first-time installation possible without pushing any pins in.

8. Once the pin is in, the link you just attached will be stiff. Work it back and forth (Slideshow image f), until it loosens enough to bend.

9. Take a look at your hands and feel proud. You have done something real today.

If you were putting on a new chain in the comfort of your home, you’ve now got an old worn out chain to upcycle! Since you know how to remove links and reattach the segments, you can use part of the old chain as a cable to lock your seat onto your bike (Slideshow image g). This is very handy in urban areas. You can also make yourself a bike chain bracelet (Slideshow image h)or an earring. You’ll need a fairly big piercing and a tough ear to get that stud through. 

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