How to repair a bicycle chain
With proper preparation, repairing a bicycle chain on the road is as easy as sticking a bicycle tube.
What you need to repair your bike chain.
To repair a damaged bike chain, you only need a chain fitting tool. It is compact and usually found in many multi-functional bike repair tools. Perhaps a similar tool is included in one of your multifunctional tools and you simply did not know what it was for.!
At home, repairing a bicycle chain can be done with a hammer and pliers, but you can’t take them with you on the road. When traveling, the chain only needs to be repaired with a lightweight chain mounting tool.
The chain breaks as usual?
often than not, the chain breaks when you pedal at full power and simultaneously shift the gear on the front derailleur. Other causes of chain breakdowns are very rare, one in a million at best. You only get a chance to meet them if you bike a lot. For example, once a nail flew out from under my front wheel, hitting the chain and hitting the sprocket. Who would have thought that this could happen?
How does a bicycle chain work?
The chain links are connected to each other using a steel pin. To remove or install a link, you must remove or hammer in the pin using a chain tool (or hammer). To repair a chain, you simply need to remove the damaged links and connect the ends of the chain to the undamaged links. On bikes with classic derailleurs, the chain is slightly larger than it needs to work, so you can painlessly remove a few links. On single-speed bicycles and bicycles with planetary hubs, links that can be removed painlessly will most likely not. So in this case, you will have to bring a new chain or an old chain with which you can remove the missing links.
Is it worth repairing a bike chain on the road at all??
It is best not to repair the chain on the road. Repairing a chain is one of the dirtiest jobs. If you are wearing new clothes, then after repairing the chain, you can most likely say goodbye to it. Probably the best solution would be to call a taxi or attach your bike to the bike lock and go home by public transport. you will come back later in your old clothes and calmly repair the chain.
How to start repairing a bicycle chain.
Let’s say you’ve changed into your old clothes and are ready to get to work. To make it easier for you to inspect the chain. turn the bike over.
Inspect the two broken ends of the chain: one end (and possibly two) is damaged and needs to be replaced. You will need to remove two chain links from the damaged end of the chain. Why do you need to remove two links, and not one. you might ask? Since the chain consists of two types of links, if you remove only one link, you will not be able to connect two links of the same type.
Where the circuit needs to be opened, place it in the groove in the chain mounting tool (see photo). The same procedure applies when repairing a worn chain.
Disconnecting a chain with and without a chain installer.
To start pushing the pin out of the chain, turn the handle on the chain installer (see photo). Try to align the axle on the chain mounting tool with the pin on the chain (sometimes it slips a little).
Do not push the pin all the way in. push it in just enough to disconnect the circuit (see photo). The remaining piece of pin must be left in the chain so that it can be easily pushed through later.
If you do not have a tool to install the chain, then you will have to find a piece of wood and drill a small hole in it. Place the pin to be removed over the drilled hole. Find a small mounting screw about the same size as the pin and use it as a stud. Hit it with a hammer to knock the pin out of the chain to the required distance. Beat him very carefully so as not to knock him completely out of the chain.
Put it back on the sprockets before connecting both ends of the chain. It will be great if your friend can help you hold the two ends of the chain in position while you connect them.
Using the chain fitting tool, insert the pin back into place (see photo). This is the hardest part of the job as you need to keep the tool in line with the pin. If you are just installing a new chain, then most chains come with a special link (lock) that allows you to remove and install the chain without having to remove the pins.
Adjust the link just installed.
Once the pin is in place, the attached link will not bend well. Move the link forward and back (see photo) until it bends well so that it can easily pass around the gears.
Look at your hands. now you can feel like a real bike mechanic.
Using the old chain.
If you just installed the new chain in a comfortable environment at home, then don’t throw the old chain away. you can use it as a supplier of replacement links! Since you have already learned how to remove and install links, you can use the old chain as a saddle lock. A good saddle is now very expensive and additional protection against theft will not interfere with it.
In addition, you can make a bracelet or earring from the chain yourself. But you have to make a rather large hole in the ear and the ear itself must support the weight of such an earring.
How to fix a chain on a bicycle. How to fix a chain on a bicycle
I used to have such a misfortune at times, on my bicycle (an ordinary one-speed a la Ukraine) the chain suddenly began to fall off. In the course of the experiment, it turned out that there can be many reasons. I wanted to be clever and generalize)).
The most elementary. The chain is not tight enough. The chain deflection should not be more than a centimeter (half a centimeter up and down). It is also impossible to pull it too much, especially on old sprockets / carriages, where its tension may depend on the position of the pedals. After adjustment, it is imperative to slowly crank the pedals several times and make sure that the chain in any of their positions is not too tight and does not interfere with the free running of the stars.
It even happens that yesterday it was pulled well, but today it sagged. This can happen if the rear wheel was not spun well enough, or (I have had this) the hub is not assembled correctly, for example, after lubrication. During the ride, some mechanism that did not fall into place jumps off and gets there, and the length of the sleeve decreases and the wheel is released.
I will move away from the topic. A dismount can also happen at the footboard with inattentive installation (this has happened). It also then falls into place in the same way and it turns out that the wheel is not spun. But here the chain is unlikely to sag, since the footboard is on the other side. But the wheel can shift and start rubbing.
A very easy reason. The carriage fell apart. If the bearings in it consist of a piece of tin with balls, then this will happen all the time. A good sleeve, in the form of a one-piece cassette, costs 10-15% more, but it will pay off. However, before buying it is better to make sure that it fits the frame. After the bearings have crumbled, the chainring may wander and the chain links do not always hit the teeth.
This reason is a logical continuation of the previous one. If you drive for a long time with a faulty carriage, then replacing its bearings creates the visual impression that everything is fine. But the axle may already be a little licked. Sometimes, to see this, you need to strain a little. Riding with such a bottom bracket will cause the chain to fall off even if the bearings are intact. It can be diagnosed “by eye” as follows. Turn the bike over, pedal and look at the chainring. She looks completely flat, but she walks crookedly. At the same time, the axis of the carriage also goes crooked.
Curve star. Perhaps it was removed with a hammer. If its course is curved, and the course of the carriage axis is even, then the point is in it.
One of the stars (most likely the front one) was eaten very strongly. Most likely they drove on a stretched or unlubricated chain. Visually, its teeth will look like billowing waves in a child’s picture)). I can’t describe it more precisely. In short, they will be licked from the load side of the chain.
Stretched chain. it does not hit the teeth of the stars, since their pitch is less than the pitch of its links. We measure. In the new chain, 24 links (12 full pairs of links) are 304.8 mm, this is the distance, for example, from the center of the first pin (link axis) of the first link to the center of the first pin of the 25th link. But when measuring, it should be as tight as possible. If the distance is more than 306 mm, then it is time to change the chain urgently, otherwise, even if it does not fall off, it already begins to lick the teeth of the stars.
Why does the bike chain fall off? articles
- Why does the chain fall off on a bicycle
- How to lubricate a bicycle chain
- How often to lubricate a bicycle chain
- Bicycle chain care
The bike chain is mostly loose due to weak tension. On newer bike models equipped with a special tensioner, the tightening process is automatic. True, the chain on such bicycles can fly off due to a malfunction of the shifting mechanism. Try changing the cable on the derailleur. If this does not help, replace the switch itself completely.
On older models, the chain is tensioned by hand. Unscrew the rear wheel and tighten it while adjusting the position of the wheel. It is not worth tightening too much, the chain may break during the operation of the bicycle. After completing this procedure, lubricate it well. This will extend the life of the chain mechanism.
Rear wheel deformation
Another reason for the chain to fall off is the deformation of the rear wheel. Otherwise, an ordinary “eight”. It also affects the handling of the vehicle and the braking performance. Especially such deformation has a detrimental effect on the brake mechanism of the rim type.
To somehow influence this situation, try to tighten the knitting needles. They should be tightened until they are all equally taut. When properly adjusted, all the spokes should make the same sound when struck. If this procedure did not help and the wheel rim did not straighten, then it is best to replace the wheel with a new one.
What to do if a chain slips on a bicycle?
Any type of cycling will always have a significant impact on its drivetrain. Why is a chain slipping on a bicycle and how to fix the problem? Chain and stars will wear off or deform over time.
To prolong their life, regular maintenance is recommended in the form of cleaning from dirt and dust and greasing. But even if all the rules for maintaining the transmission are followed, its parts will still wear out over time. Then their replacement is required.
Why does the chain slip on a bicycle
The first symptoms of transmission malfunction occur when shifting gears while depressing the pedals. Cyclists often notice this immediately when going uphill, because then the load on the bike is one of the strongest.
Reasons for chain slippage on a bicycle:
- stretching of the chain due to wear of its links (in particular, their thinning);
- wear of the stars;
- two reasons at the same time.
The most common cause is chain stretching due to long-term use of the bike, which causes the chain components to wear out. The main indicator of chain wear is its length (normally it is 304.8mm).
As a result, the spring on the derailleur does not tension the chain. This contributes to chain sagging and a decrease in the quality of gear shifting (which is especially noticeable when changing from low to high speeds).
It is almost impossible to restore the elasticity of a worn part. Therefore, there is only one way to solve the situation. replacing the chain.
The stars can deform due to wear or mechanical damage caused by impact. In both the first and second situations, it is impossible to restore the cassette teeth. Therefore, replacement with a new one is required.
Both factors at the same time
Also, the chain can slip due to the stretched chain and wear of the sprockets at the same time. This pattern is due to the following: as the distance between the chain rollers decreases, the sprocket teeth also narrow. To determine the degree of wear, it is enough to compare the widths of new and worn stars.
The reason for the one-time wear of the chain and sprockets is also incorrect gear shifting. This leads to a strong distortion of the chain, and on some parts of the parts there is increased pressure, and they wear out faster.
What to do if the chain slips?
If the chain slips on the bike without gears, it is enough:
- unscrew the nuts in the area of the rear wheel axles;
- pull the wheel towards you;
- tighten the nuts, controlling the immobility of the wheel to the center of the frame.
Measuring chain stretch
Stretching the chain does not imply its elongation, it occurs when the links wear out, due to which the distance between them increases, and the chain wears out. There is some discrepancy in the pitch between the sprockets and the length of the chain link in the worn part. As a result, the cassette and the entire transmission system do not work properly.
To determine the degree of wear, you will need:
- use a tape measure to measure 24 chain segments;
- this can be done without removing the chain from the bike. on the top tensioned part;
- normally the length of 24 segments is 30.5 cm;
- the distance from 1 to 25 axis is measured.
Based on the results obtained, they understand how necessary a chain replacement is:
- 30cm 48mm. new chain condition;
- from 30cm 48mm to 30cm 64mm. normal length;
- from 30cm 64mm to 30cm 79mm. the length indicating the chain is worn out, replacement is required, otherwise the first problems with the transmission will appear;
- over 30cm 79mm. critical stretching, in such a situation, replacement of both the chain and cassette (or sprockets) is most often required.
With a stretch of 30.8cm, the ride becomes unbearable. The chain either gets stuck or slips and dangles. Some use a squeeze to shorten the chain by a couple of links, but this does not help to solve the problem for a long time, and as a result, they come to a solution to replace parts.
Replacing the chain and cassettes
When changing the chain, cyclists have difficulties that can be avoided by following the following algorithm:
When replacing cassettes, use:
- key with chain;
- retaining ring remover for bike cassette.
Algorithm for removing the cassette:
- remove the wheel;
- install a puller so that the spitz falls into the retaining ring;
- place the handle of the key with the chain (whip) to the right of the cassette, and on the bottom of the chain, on the star, so that its links are tightly installed on its teeth;
- put an adjustable wrench on the cassette remover, and turn it counterclockwise while holding the whip and preventing the stars from spinning;
- unscrew the locking wheel;
- remove and unfold the stars and washers in the order that there is no confusion during installation. this is the final stage of removing the cassette.
Algorithm for installing the cassette:
- there are various grooves and pins with the same size on the sleeve and stars, with the help of which the installation will be in the required order;
- before installing the cassette, lubricate the thread of the retaining ring;
- put on stars and spacer rings alternately;
- some models of cassettes require pressing the last asterisk during installation;
- after installing the last sprocket, screw the retaining rings, check the correct installation of the sprockets, and if correctly installed, tighten the retaining ring with the cassette puller until it stops.
To eliminate the risk of the chain flying off the stars, cyclists install anti-vibration devices. They can be equipped with rockrings. special plastic parts to protect stars from impacts when passing obstacles. curbs, pits and other.
How are they installed with ISCG dampers:
- prepare tools: hexagons, squeeze, carriage pullers, threaded fasteners, keys for removing bonds and grease;
- remove the stars and connecting rods so that the large star is set to the middle one;
- screw rockring;
- select the optimal position of the roller (with a 6-inch suspension travel, the position is strictly at 12 o’clock, with a smaller one. at 11:30);
- tighten the bolts;
- drip in the area of the fastening bolts;
- install connecting rods;
- put stars on a chain;
- fasten the rollers;
- align the distance between the inner pancake and the star so that it is identical to the distance between the outer one and the star;
- the chain should not touch the pancakes;
- after tightening the bolts all the way.
If, during overshoots, the size of the chain and stars are correct, then the problem lies in the breakdown of the switches. This usually happens with a recent replacement of parts, and will wear in over time. In this case, the inconvenience is temporary. Other situations may require assistance from a service technician.
What to do if the chain is off the bike
Today we will consider the moment when the chain flies while riding a bicycle. Firstly, at high speed it can lead to dangerous injury, and secondly, it is a bicycle breakdown. The main reasons that can lead to this are the following:
Your chain may be loose. If the bike has no gears, then all you need to do is unscrew the two nuts on the rear wheel axle, and then pull them towards you. By doing this, you will see that the chain will stop sagging. If the bike has speed, then you have to try. You will have to change the derailleur as it has a spring that pulls the chain automatically. It loses its firmness over time.
Curvature of links. If you notice that these links are bent, then you have two options: complete replacement of the chain, or getting rid of bent links.
Deformation of the teeth on the star. Everything is pretty simple here. The teeth can be deformed, for example by impact. You need to replace the cassette with a new one.
Stretched chain due to long-term use. It is unrealistic to restore the elasticity of the chain, so all that remains is to replace the chain with another.
Incorrectly configured switches. This only happens on bicycles with gears. To prevent this from happening, you need to adjust the rear derailleur as accurately as possible. It is easy to notice this: the chain will randomly jump to another gear during the pedaling process, but you will not press on the shifter petal.
In general, we recommend that you simply maintain your bike more often.
How to tension and adjust the chain on a bike
Today we’ll help you figure out what problems you might have with your bike chain and how to fix them. Mikhail Kucheev, one of the leaders of the project “Sam to Sebe Bicycle”, will tell you about everything in detail.
During the trip, you may experience the following with the chain
The chain flew
Let’s see why the chain flies. There are two options: either you have a bent sprocket on the system (the system is a front set of sprockets), or the speeds are poorly adjusted.
If you have a bent star on the system, in this case, you can continue moving simply by switching to a different speed at which the star is not bent. But if you use all the speeds while driving, then in the future you will have to replace the bent star. If the system is collapsible, you will only be able to replace one damaged star. If the system is non-separable, you will have to change the entire system along with the connecting rod.
If everything is in order with the connecting rods (what is a connecting rod?), Then your speeds are poorly set. On each of the derailleurs, both front and rear, there are adjusting bolts that prevent the chain from going over extreme speeds. If they are incorrectly adjusted, then the chain will fly off. If the chain falls off the largest sprocket, then you need to screw in a bolt with an L index, which means low. the lightest gear.
It must be screwed in until the stars on the switch are parallel to the large star. The same from the reverse side: if your chain flies from the smallest sprocket, you need to screw in a bolt with the index H (high).
Twist it until the switch is parallel to the seventh speed.
If at the front the chain falls from the small chain to the frame, then tighten the bolt low.
To properly adjust the bolt labeled low, you need to set the lightest speed on the bike and screw it until there is a 1 mm gap between the inner derailleur frame and the chain.
If the chain falls from a large sprocket to the connecting rod, then screw in the high bolt.
To properly adjust the high bolt, you need to set the bike to the highest speed and tighten it until there is a gap of 1 mm between the chain and the outer derailleur frame.
These were the most common reasons for chain failure. Now let’s talk about her breakup.
The chain broke
The most common cause of chain breaks is when shifting gears under load, such as when driving uphill. When a chain link breaks, it can either rivet or break. If the link is riveted, you can try riveting it back. You will need a chain puller to do this, so it’s best to carry it with you at all times. If the link breaks down, it is necessary to remove it and the link adjacent to it, too, and rivet the chain using the same puller.
Putting the chain back on is easy. To do this, pull back the rear derailleur while loosening the chain and place it on the front sprocket.
Today you learned why the chain can fly off and break, as well as how to solve these two problems with your own hands.
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Music used in the video:
JK Soul. I know this (Original Edit)
What to do if the bike chain breaks?
Modern bike chains may not be very common, but they still break. Usually, when the chain breaks, a pair of links at the break point bend and fail. And, as a rule, this happens at the most inopportune moment, for example, at intersections or at competitions, or on a beautiful day when you went for a bike ride with friends. The cause of breakage can be anything from poor shifting under load, which leads to the detachment of the outer chain plate from the pin, high wear, or even improper installation and adjustment of the bike.
What to do (tips from the masters of the bicycle genre)
It is best to replace them with new links from the same type of chain. Therefore, on a long trip, you should grab a piece of chain from 8 to 10 links. 2. Carry a chain lock with you. The lock consists of two halves of a link that are connected to each other. No additional tools are required to install the lock.
If you do not have a lock and a spare piece of chain with you, you can shorten the chain by removing a couple of damaged links. True, this requires a tool called squeeze. Always have a Rem kit in your backpack! Please note that after shortening the chain, some sprocket combinations may not work.
We offer step-by-step instructions to fix a circuit malfunction on your own in a few minutes using the correct tool. squeezing the chain (it must be in your backpack), but be careful, because the restored connection in the chain will not be as strong as when the link is replaced with a new one and the chain may break again.
So: 1. Remove the broken chain from the bike. 2. Check the rest of the links, which may be bent or twisted and cause jump under load. 3. As a result, you can see that at the edges of the chain, different combinations of halves of links such as dad (inner link) and mom (link with outer plates) are possible, depending on how the chain broke.
Broken link to be removed.
In order to connect the chain back without spare links, you need to use a squeeze and connect the inner link (dad) at one end and the outer link (mom) at the other.
Some chain pushers are equipped with two chain link slots. The inner section only serves to repair the hard links that may appear after the chain is repaired, but you will only need to use the outer slot for inserting and removing links. But maybe yours has only one slot. Some puckers are screwed to accommodate different link widths. If you have one, just screw the trim all the way down after you install the link in the squeeze slot. This way, the link will be held in place while you work with it. When removing damaged links, keep in mind that the chain length should remain as close to its optimal length as possible.
To leave an inner link (male) at the end, simply remove the entire pin of the broken link from its hole. The outer plates will fall out, leaving only the inner link. Please note that the inner link roller must stay in place (the round roller between the inner link plates), it should not fall out, although it sometimes tries to do so. 7. Prepare the opposite end of the chain with the outer link (mother). This part is more difficult. Place the chain link first in the outer section of the chain link and make sure the chain link pin aligns exactly with the link pin. Start pressing on the pin, but the key is to stop before it is completely out of the outer plate. The goal is to push it outward enough to remove the broken link, and if done correctly, you can pull it out by bending the outer plate slightly. When you pull out the broken link, you will see the extruded pin protruding into the link from the outer plate by about a millimeter. If you accidentally squeeze a pin out of a link entirely, you might be better off doing it all over again on the next section of the chain. it is not recommended to press the pin into the link if you squeezed it out completely. In addition, leaving the pin in the outer link plate to stick out a millimeter inward makes it much easier to connect the chain when you put it on the bike. when you connect the inner link at one end and the outer link at the other, they will hook slightly and you do not need to hold the chain.
Chain ends with a new outer link (female) on the left and the other end with an inner link (male) on the right.
You are now ready to install the chain on your bike. To reduce the chain tension (this will make it very easy to install), move your rear derailleur to the smallest sprocket and do the same on the front (if you have one). Stretch the chain as it should be in normal condition, but make sure that the pin, which is at one end of the chain and is almost completely sticking out of it, sticks out to the outside of the bike, so it will be easier to work with.
The chain pin protrudes outward from the bike and is ready to install.
Connect the two ends of the chain together. If you have pulled the pin on the end of the chain with the outer link as much as needed, you should easily interlock the ends of the chain and do not need to be kept from disconnecting. If this is not the case, you will have to keep the chain from disconnecting when you press the pin into the link. You can use this method: take a 4-inch piece of an old knitting needle, bend it into a “C” shape and use it to hook your chain. Before you press the pin into the chain, make sure the holes in the link to be connected and the pin are straight. If the pin is not in line with the holes in the outer link plates, you will simply break the link, or the pin will not fall into the hole and on the opposite plate, as a result, the chain will be unreliable and unsafe to ride. When you are sure everything is in alignment, start pushing down on the pin until it protrudes the same amount on both sides of the outer link. Depending on your chain, the ends of the pin may be very close to the edges of the outer plates. It is important to make sure that the pin extends the same amount at both ends. Carefully check the new connection for defects in the chain, for example, twisting of the plates during installation.
Using a squeeze to install a pin. You can work out where the links are rigidly connected with your hands
There is a high probability that the chain will not rotate at the new junction. This is because the outer plates are pressed against each other with a squeeze when you press the pin into it. You can easily find such a rigid link connection when you pedal backwards and observe the chain on the idler roller. 11. There are two ways to correct this situation: by hand or squeeze. Grasp the chain with one hand on one side of the clamped link and with the other hand on the other side, with your thumbs in place of the rigid connection. Bend the chain lightly from side to side directly at the rigid connection. One or two attempts are enough for the chain to rotate freely in the place of the new connection. Another method of correcting flexion is to use the internal squeeze slot to slightly nudge the pin at the rigid connection. This method is also very effective.
Attention! Before you continue riding please note that you have removed the links from the chain and it is now shorter than it was. If the chain was originally the right length, then now it may be too short, especially on large stars. Be very careful or you will need to replace the rear derailleur and cock!