Content

• Method 2 of 2: Replacing a Broken Chain
• Tips
• Caveats

1 Determine where the chain has come off. Sometimes the chain does not break, but simply leaves its normal position. Since it is still located on the front and rear derailleurs in this case, no special intervention is required. All you have to do is fit the chain back onto the sprocket. If the chain fell off while riding, get off the bike, place it on its side, with the sprockets up, and find the place where it slipped off the dismount. Normally the chain will fall off the front sprocket but remain on both derailleurs.

• Look for places where the chain might have jammed. These areas may need to be sorted out before the bike can be cycled again.

2 Use the eccentric release if the chain is pinched. As mentioned above, sometimes the chain will get stuck between the rear sprocket and the frame. In this case, loosen the rear wheel eccentric and unscrew the eccentric nut so that the chain can be removed.

• The eccentric is opened by releasing a small lever located in the center of the rear wheel. Then unscrew the nut on the opposite side of the lever and release the chain.
• Remember to clamp the eccentric back before riding. The nut should be tight enough so that the lever is not clamped too tight or too loose. If the lever is too tight, loosen the nut slightly and try again. If the lever is clamped too easily, the nut must be tightened.

3 On a bike with a rear derailleur, loosen the chain tension and slide it over the front sprocket. Most bicycles have a spring in the rear derailleur to keep the chain tensioned while riding.Overcoming the resistance of the spring, tension the chain so that it can be slipped onto the smallest chainring. Then release the chain and check that it is sufficiently tensioned.

• As a rule, you can continue driving after that. At first, the bike may move somewhat erratically until the chain sits in the correct position.

4 On a bike with no speeds, tighten the chain sprocket by rolling the pedal. As mentioned above, in many bicycles, for example, in "wood grouse" there are no speed switches. In this case, put the chain on the rear sprocket, and, hook it into as many teeth as possible on the bottom of the front sprocket, roll the pedal back. The chain should catch on and start winding around the sprocket. When the chain is wrapped around the last top tooth of the sprocket, it can function normally.

• It will be easier to pedal if you raise the rear wheel. To do this, you can put the bike on a rack or put some kind of material under it. You can also ask a helper to hold the rear wheel suspended or, in extreme cases, just turn the bike over.

5 Smoothly pedal forward until the desired speed is established. Sit on your bike and start moving slowly. If you have a speed bike, the chain may jump to the speed it was at before breaking. Otherwise, adjust the speed yourself until the chain friction disappears.

• Note that if the chain falls off on fixed speed bikes it could be a sign of poor chain tension. Therefore, adjust the chain tension before the next ride.

6 Perform a follow-up check. Set the most comfortable speed before the first post-service ride. Shift all speeds on the front and rear derailleurs to make sure the chain does not squeak anywhere.

Method 2 of 2: Replacing a Broken Chain

1. 1 Get a new chain and replacement tool. To replace a bike chain that has come off completely or broken, you need a new chain that fits your bike and a replacement tool (squeeze) to remove the old chain and install a new one. You will also need a pin to connect the new circuit, but this usually comes with it.
   • All of these can be purchased at a sporting goods store or a specialist bike store.
2. 2 Assess the breakdown and try to do something about it. If the chain breaks while riding, roll the bike to the curb and lay it on its side, with the sprockets facing up. Inspect where the chain is broken - most likely the chain is dangling from the sprocket, and you can easily find the two broken ends. In a conventional chain, the links are connected to each other by means of a pin (pin, cylindrical cup) that holds the plates of the inner link through which the pin passes, and a roller on top of the cup. Therefore, if you are an experienced cyclist and carry a chain fitting tool and spare parts, you can repair the chain yourself and re-tension it. Basically, bicycle chains fall into three categories:
   • Chains with special rivets. These chains are supplied with special rivets from the manufacturer. If you do not have such rivets with you, then, to repair the chain, you will have to get to the nearest bike parts store.
   • Trailing link chains. These chains have a special link with two rivets that connect the ends of the chain. If this connection breaks, then you will have to replace this link in order to repair the chain.
   • Chains with "normal" links. Old, traditional chains are made up of standard links, each of which can be replaced with the same (if you have a tool).
3. 3 Remove the broken chain. If you find that replacing the chain will be easier than repairing, then the first thing you need to do is remove the old chain. If it breaks completely, then just pedal and it will fall off the sprocket by itself.If the chain does not fall off during rotation, then it must be disconnected manually. This can be done with a squeeze, available at almost any bike store.
   • To open the chain with a squeeze, position the chain pin against the squeeze pin. Then tighten the pin screw while pushing out the pin. If you plan to reuse the chain, do not remove the pin completely, but only to a level sufficient to disconnect the chain links.
   • After you disconnect the chain, pedal to release the chain from the cassette. If you want to replace the chain, remember to count the number of links in the old chain (on bikes with a rear derailleur, take into account the error). Also consider your drivetrain type as it determines the type of chain to fit your bike. For example, a nine-speed transmission requires a nine-speed chain.
4. 4 Raise the rear wheel. The next step is to thread the new chain through the rear derailleur. To do this, you will need to spin the rear wheel, which will be much easier if it is not on the ground. If you have a bike rack, or a post in the wall that you can hang your bike on, use this. If you don’t have such benefits, simply lift the back of the frame by placing something under it, such as a box or cinder block.
   • Also pay attention to the speed switch. The rear derailleur needs to be shifted to the highest gear, and for the front derailleur down to the lowest.
5. 5 Thread the chain through the rear derailleur. On most modern mountain bikes, the rear derailleur is a spring-loaded system of mechanisms that descend below the main rear sprocket. Passing the chain through this mechanism requires special attention, since the safety of the ride depends on it. Take the “mother” (end of the chain without pin) of the pre-sized chain and loop it around the lower idler pulley and then around the upper one. If done correctly, the chain will run in an S-shaped manner. If S is uneven, it is possible that the chain does not fit into all the grooves of the rollers, or it is caught on something.
   • There may be a small metal eyelet between the rear derailleur idler rollers. The chain must not touch it.
   • Some bicycles, such as wood grouse (fixed-gear bicycles) or bicycles with planetary hubs, do not have a rear derailleur. In such cases, simply pull the chain over the sprocket and pedal as advised in the next step.
6. 6 Slide the chain onto the rear cassette. On mountain bikes, the rear cassette is a set of multiple sprockets attached to the rear wheel. After threading the chain through the switch, slide it onto the the smallest an asterisk in the cassette. After making sure the chain is securely through the derailleur and rests firmly on the sprocket, pull it slightly.
7. 7 Thread the chain through the front derailleur. Most modern mountain bikes have a metal mechanism in the front sprocket area that moves the chain from one sprocket to another. Guide the front end of the chain through this switch. If the chain does not reach, turn the rear wheel a little further.
   • Capercaillies do not have a front derailleur, so simply slide the chain over the front sprocket as described in the next step.
8. 8 Slide the chain over the front sprocket. Place the chain over the smallest chainring. Pull it well and check that it rests on all the teeth of the sprocket, then crank the pedals.
9. 9 Connect the ends of the chain. Now that the chain has been securely routed through all of the drivetrain, you can connect the ends and enjoy your ride again. Place the link to be connected (mum and dad) into the squeeze, on the stop closest to the fixing screw. While adjusting the position of the chain, move the pin to the pin to be clamped so that they are coaxial. Tighten the link with the retaining screw. Rotating the handle, clamp the pin into the link.Check the depth of the pin's immersion at all times. Failure to comply with this subtlety can lead to damage.
   • One useful tool is the C-clip (a small thin piece of metal) that helps hold the two ends of the chain side by side. This makes the job a lot easier as you don't have to hold the two ends of the chain yourself. A bent paper clip can serve as such a C-shaped bracket.
   • In some cases, when connecting a chain without master links, the pin you connect the ends of the chain with can make the link inflexible. In this case, the pedal may stick at a certain point. To fix this, work the links on either side of the jammed link in a direction perpendicular to the rotation of the chain.

Tips

• Every cyclist should have basic knowledge and repair skills. This way you can not only save on maintenance, but also not find yourself in a hopeless position, being far from the bike workshop.
• It is not uncommon for the chain to fall off from time to time, but if this happens too often, specialist assistance may be needed.
• If the chain is still slack and you are unable to seek professional help, you may need to remove several chain links to shorten the chain. But don't do it yourself if you don't know how to remove the links correctly!
• If you can, purchase a special tool called a chain tensioner. Buy yourself a couple and follow the directions on the package. Typically, you will need a Phillips screwdriver and a specific size allen wrench. These tools will help you maintain the correct chain tension.

Caveats

• Tie back long hair, tuck in clothing, and zip up all the way before repairing the chain.
• Do not put your fingers in the chain, otherwise they can be injured or lost altogether.
• When doing repairs, wear gloves whenever possible to prevent grease on your hands.