The chain flies off the front sprocket of the bike

Reasons for chain slippage through the stars

Transmission misbehavior problems occur under load: pedal pressure when shifting gears. Slippage is especially pronounced when driving uphill, when this load is at its maximum. This pattern is equally true for a single speed bike and a speed bike. Let’s figure out what serves as a prerequisite, and whether it can be fixed.

The reasons why chain links break off the stars are simple and transparent:

  • elongation of links due to wear;
  • the teeth of the rear and front sprockets are worn out;
  • both factors at the same time.

The latter option is most common if the chain or cassette has not previously been changed separately.

Chain length is an indicator of chain wear. The standard size is 304.8 mm. Stretching leads to the fact that the teeth of first small, and then large stars are more sharpened, due to which the efficiency of gear shifting on a high-speed bicycle decreases several times. Especially noticeable lengthening will affect the transition from lower to higher speeds.

If the distance between the chain rollers increases, the width of the sprocket teeth decreases. You can easily notice the development with your own eyes. To calculate the degree of sharpening, the thicknesses of the teeth of a worn and new star of the same size are compared.

And finally, another reason why the transmission wears out quickly is incorrect gear shifting. For simplicity, let’s remember once and for all:

  • In front, the stars are counted from the smallest.
  • Rear cassette numbering starts from largest sprocket.
  • It is necessary to combine higher gears with higher gears (large stars in front and small ones in the back), and vice versa.
  • Since there are fewer sprockets on the front cassette, there are several sprockets for each sprocket on the rear cassette. For a standard 3X8 system:
Front one 2 3
Rear 1, 2, 3 4, 5, 6 6, 7, 8

Correct use of the gearshift system avoids excessive chain skewing, which would cause tremendous wear on parts.

Why does the chain slip on a bicycle?

Any bike ride, be it a speed race or a simple ride, has a significant impact on the drivetrain. During the ride, the chain and stars experience significant friction against each other, as a result of which they become unusable over time.

Timely lubrication and debris removal is essential to reduce friction and increase transmission life. However, even with proper care, the cyclist can face a problem of wear when the chain slips, the gears shift poorly, or the engagement of the links on the teeth of the sprockets is lost.

How can you fix the problem

In this section, consider a situation where the chain starts to turn or fly off, the switches with the tensioner are set correctly. As already found out, the problem is caused by wear and tear. A radical option is to change the cassettes along with the chain. But there are also more gentle options that will allow the system to serve more.

Quick Fix for Dropped Chain while cycling. front derailleur

So, remove the chain from the bike, straighten it and measure its length. By its size, you can judge its wear:

  • up to 306.4. slight elongation, the problem is only in the stars;
  • up to 308 mm. average wear.
  • over 308 mm. completely unusable.

After measurements, you need to inspect the front and rear cassettes. When the chain is stretched to 307.9 mm, wear is likely to show up on small to medium rear sprockets. They can be replaced separately without buying a new cassette.

Replacement is recommended at average wear, however, at first, the inaccuracy of the transfer and slip can only worsen. This is due to a mismatch between the roller spacings and the width of the teeth. Over time, the transmission components will rub together.

Stretching over 308 mm no longer allows you to ride a bike calmly. The chain constantly slips and dangles, can get stuck in the space between the sprockets. The correct solution is to change it along with the cassette. Can also be shortened by two or three links using a squeeze.

Is there an alternative? Yes, it exists, and it is a circuit breaker. In general, these devices are used for safety purposes in cycling when the chain is likely to fly off the stars. But with their help, you can maximize the riding time with worn out parts.

The dampers consist of a disc (rockring) and rollers. There are also rollerless models, where the chain “calms down” only by the frame. Dual roller versions are used for high speed bikes where each of them corresponds to two chainrings.

Adjusting the derailleurs on a new bike

Slips and inaccurate gear changes under normal wear indicate deranged derailleurs. This problem usually occurs with a new bike, or if the chain and sprockets have recently been replaced.

General scheme for adjusting switches:

For the rear sprocket, you still need to set the correct position of the tensioner, which will compensate for the chain slack.
Bicycle Rear Derailleur Setting:

  • Loosen the screw and remove the drive cable.
  • Set low gears by placing the chain in the 1: 1 position.
  • By turning screw L, the alignment of the guide roller with the star is achieved.
  • Install the cable into the derailleur.
  • Turning the pedals, set the highest gears: the chain on the small sprocket in the back and the largest in the front.
  • Using screw H, match the roller and the active sprocket in the same plane.
  • The correct tensioner position is 5mm from the lowest sprocket in a 1: 1 chain position.

Similarly, the front derailleur is adjusted according to the scheme: setting the restrictions on L. adjusting the top gears on H. adjusting the tension of the drive cable. However, first you need to check the coincidence of the switch roller with the plane of the outer stars. Perhaps just setting the rear derailleur will be sufficient. And of course, checking the operation of the transmission, in particular, the chain tension, in practice.

In principle, adjusting the switches will last for a long time. The correct use of the speed system will help to reduce the wear rate, and the timely elimination of negative factors will allow the transmission to last as long as possible.


There are a number of reasons why the chain fails. They are listed below:

  • weak tension (applies to both bicycles without gears and with variable transmission);
  • curvature of one or more links;
  • deformation of one or more teeth in the chainring or chainring;
  • the chain is stretched as a result of prolonged use;
  • front or rear derailleur incorrectly.

Now let’s take a closer look at each problem. Here we will also offer solutions to emerging difficulties.

What to do if the bike chain falls off?

During the operation of the bicycle, the owner has to deal with a situation where the chain comes off during the ride. This situation is dangerous when driving at high speed, as well as in the process of screwing down a hill. Even if you use slip-on pedals with shoes to keep your foot from flying off the pedal, when the chain falls off, the cyclist can sprint over the handlebars or fall on his side. In this article, we will look at the main reasons why the bicycle chain flies, and also give practical advice on how to fix this breakdown.

Reasons for chain slipping on a bicycle under load, repair step by step

Cassettes, chains and other bicycle parts are subjected to constant loads during operation, so their deformation is not excluded. Regular cleaning and lubrication will significantly extend the life of the parts, but they are not a solution to the problem. Answering the question why the chain slips on a bicycle under load, it is worthwhile to understand that even following all the recommendations for caring for the transmission does not exclude the gradual wear of the elements. In this case, you will need to replace them.

Deformation of one or more teeth in the chainring or chainring

Why can the teeth warp? The first obvious reason is due to impact, the second is due to severe wear. In any case, if the chain falls off solely due to problems with the teeth of the cassette, then it is necessary to replace it with another one.

Adjusting the switches on the new bike

The chain comes loose when shifting gears on a high-speed bike, even when there is no wear. The reason is incorrectly configured switches. The problem is inherent in new bikes, and is also possible after replacing transmission parts. General scheme for adjusting the switches when the circuit is bouncing:

It is important that the chainring tensioner is correctly aligned to compensate for chain slack. Step-by-step instructions for adjusting the rear derailleur:

  • Loosen the screws and pull out the drive cable.
  • Set the gears to low, setting the path to the 1: 1 position.
  • Turn the screw until the guide roller aligns with the star.
  • Install the cable into the switch.
  • Scrolling the pedals, adjust the highest gears: the tract in front on the largest sprocket, in the back. on the smallest.
  • Turn the screw until the sprocket aligns with the roller. The correct value for the tensioner position is 5 mm.
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3 Main Causes Of A Chain Drop How To Fix Them. Solving Bicycle Chain Problem.

Following the same step-by-step instructions, adjust the front derailleur. Upon completion of the adjustment, check the operation of the transmission, the tension of the tract under load. A properly tuned speed system will reduce wear and tear and, thanks to timely troubleshooting, the transmission will last for a long time. After adjusting the switches, you don’t have to wonder why the chain jumps.

Rear wheel deformation

Perhaps the problem is the deformation of the rear wheel. One of the most unpleasant cyclist problems is the so-called “eight”. “Eight” is the deformation of the wheel, violation of its shape and the inability to perform functions. This problem is eliminated by tightening and loosening the spokes with a special spoke wrench. To do this, the wheel is removed, the affected area is determined and the central spoke of the “figure of eight” is highlighted. Then the needles are pulled through one.

Worn chain-cassette-system

A bicycle, like a car, has its own consumables. This includes all the components of the chain drive. Why do the chain and stars need to be changed periodically? Due to wear:

  • The chain is constantly lengthening. This results in an increase in the distance between the elements of one link (rollers). And the interval grows due to the boring of the axes (pins) of their seats.
  • The chain, lengthening, changes the profile of the teeth or, as they say, sharpens the teeth for itself. The wear mechanism is not closely illuminated, but as a first approximation it can be seen that there is plastic deformation of the teeth or the so-called “pulling out”.

It is quite reasonable to ask why the chain slips on a high-speed bike only on some sprockets. The point is, everyone has their own favorite speeds. Usually there are two, maximum three small rear sprockets and one in front. The chain sharpens them, while others remain in the “novya” state, so the chain does not slip on unpopular gears.

Often a new chain jumps over the stars. This is due to the fact that it is installed on old stars. The teeth are stretched out for a larger pitch between the pins than on a new bike chain, which is why slip occurs. often the cassette is to blame, less often the system is also to blame.


It is often used as the most accessible tool when there is no caliper or caliber at hand. Using a tape measure, the total length of the first 24 links (from the center of the first pin to the middle of the 25th axis) is measured, based on which the conclusion is drawn:

  • Up to 304.8 mm. The chain is new.
  • 304.8-306.4 mm. You can ride.
  • 306.4-307.9. Change.
  • than 307.9. Replace chains and cassette.

There are several reasons:

  • Strong shaking while driving
  • Too stretched chain
  • The chain was recently oiled
  • Switch incorrectly configured
  • One of the links in the chain is biting, not turning.
  • Sprocket bent or cassette damaged

Most often we deal with a combination of factors at once.

The most unpleasant situation when the chain falls into the space between the frame and the star occurs if at one of the moments the chain is “in an advantageous” position for this. All of the factors described may play a role.

The principle of a light bulb in the mouth works here. it falls in one direction, but does not get back. But, unlike a light bulb, the situation can be corrected without the help of a traumatologist.

Depending on the type of bike you are using, there are two different options depending on the type of transmission.

Reasons why the chain flies off the stars on a bicycle:

Most common cause related to single and multi-speed bikes.

How to check the tension of the bike chain? Its sag on a single-speed bike should be 10-15mm maximum in the center between the sprockets.

details about this are described in the article “How to correctly determine the length and tension of a bicycle chain” and we will not repeat ourselves here.

Curvature of one or more chain links. Usually one link is enough. It occurs from impacts due to careless handling or falling of cyclists.

Single-speed cycling is more robust and such problems are extremely rare there. In more gentle multi-speed ones, this happens, but it cannot be said that very often. There is no way to treat it. It is necessary to either remove or change the link, if the length of the chain allows, or replace it all. If the chain is already partially worn out, it is better to immediately change it to a new one.

Aligning the link with a hammer on the anvil or pliers is unrealistic. It is ideal not to align it directly, but in this form it will still accelerate the wear of the sprockets and fly off them.

Deformation or wear of the sprocket teeth in the system or cassette.

Deformation can only occur from impacts, and wear, especially on bikes with gear shifting, is a natural and inevitable process.

In both cases, it is better to change the asterisks, and if they are not the newest anyway, there is a reason to replace the entire cassette at once.

I would like to clarify one more thing. To insert into place the curved teeth of the sprockets “with the help of a hammer and some kind of mother” is, at first glance, a simple and obvious business, but not rewarding and often useless. Although the craftsmen do everything, but then you will ride such a bike, so think for yourself. Ideally, it will not work out exactly: this means that the wear rate of the chain will increase, and the risk of dropping it from the sprockets will remain.

This is very rare on single-speed bicycles, but common on multi-speed bicycles. How to correctly determine chain wear is described here and we will not repeat ourselves either.

Front or rear derailleur incorrectly configured.

This only happens on bicycles with gear shifting. The problem manifests itself when, when pedaling, the cycle itself jumps to another chainring. In this case, you need to set the switches correctly. This is usually done with two adjusting bolts, designated by the letters L and H. But we will not consider all the nuances of this process within the framework of this article, especially since there are many materials and videos on this issue on the network.

Why Mountain Bike Chain Slips Under Load

There are, in fact, only two reasons. The rear derailleur is incorrectly adjusted or the chain and sprockets of the system and / or cassettes are worn out.

What to do if the chain fell off the bike

Imagine this situation. you are riding, drove quite far from your home and then a “bryms”, a bicycle chain flies off. The problem is not the worst, but if you have never put the chain back in place before, difficulties may arise. It is especially unpleasant that cyclists usually do not have any tools with them.

This article is planned as a quick emergency guide that can be used in the field. And also, below we post a video so that you can quickly solve this problem.

First, be prepared to get your hands dirty with oil. As they write on modern memes: “You can’t just take and put the chain in place without getting your hands dirty”.

Secondly, problems will begin not just when the chain has fallen off the bike, but when the chain gets stuck between the system and the frame. This is the worst case. But let’s take everything in order.

First, let’s figure out why the bike chain flies at all.?

Elimination of breakage

Often, users are interested in what to do if the chain on the bike flies constantly. The repair algorithm depends on the type of bike. To eliminate the cause of scrolling the tract while loading the pedals of a conventional bicycle, you need to:

  • unscrew the rear wheel axle nuts;
  • pull it towards you;
  • ensuring the immobility of the wheel in relation to the center of the frame, tighten with nuts.

Performing the same work on a high-speed bike is more difficult. First, you need to measure the stretch of the chain. in the worn part, the size of the part does not match the pitch between the teeth of the stars. The result is a transmission failure. The level of production must be determined as follows:

  • using a tape measure, measure 24 segments of the tract on the stretched upper part (normal value is 30.5 cm);
  • determine the distance from 1 to 25 axis.

In this way, the degree of stretching is determined. Fault finding affects transmission performance. If the chain falls, the timely replacement of the part will avoid many problems in the future.

Results from 30 cm 64 mm to 30 cm 79 mm indicate that stretching has reached a critical state. In this case, install a new chain and sprockets.

To avoid problems, you should adhere to a certain algorithm. Instructions on how to put the chain if it flew off on a bicycle with several speeds:

  • place the link on a special squeeze so that the pin is in front of the axis;
  • slowly turn the handle until the pin is almost completely squeezed out;
  • install a new chain, starting to fix the switches with small stars;
  • put a chain on them, taking into account the location of the tension rollers;
  • aligning the links, clamp the chain, press in the axle.

After installing the chain, turn the pedals to check the operation of the element. It is advisable to do this with pressure. If all the steps are performed correctly, the chain on the bicycle will not fly off, sag.

To replace the cassette, you will need the following tools: an adjustable wrench, a wrench with a chain, and a retaining ring puller. Step-by-step instruction:

  • remove the wheel;
  • install the puller, making sure that the spitz is in the retaining ring;
  • make sure that the handle of the key with the chain from the cassette is located on the right side, and on the teeth of the star from below so that its links lie tightly;
  • put an adjustable wrench on the cassette remover, holding the whip to prevent the stars from turning; turn it counterclockwise;
  • unscrew the locking wheel;
  • dismantle washers, stars, laying them out in the same order to facilitate subsequent installation;
  • pins, grooves of bushings and stars are of equal dimensions, which facilitates correct installation;
  • put on stars and spacer rings in turn;
  • install the extreme gear, screw on the retaining ring, check the correct assembly, tighten it up to the stop with a puller.
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To prevent the chain from slipping off the rear large chainring of the bike, it is worth installing a damper. Rockrings, which they are equipped with, protect the elements from damage while overcoming obstacles.

Step-by-step instructions on how to install dampers:

  • prepare tools: hexagons, rubber clamps, wrenches for removing bonds, carriage pullers, grease, squeeze;
  • dismantle the stars with connecting rods so that the large one is located on the middle one;
  • screw on the rockring;
  • determine the correct position of the roller;
  • tighten the bolts;
  • drip in the area of ​​the fastening bolts with threaded clamps;
  • install connecting rods;
  • put stars on the tract;
  • fix the rollers;
  • align the spacing between the inner pancake so that it coincides with the outer one; the chain should not touch the pancakes;
  • tighten the bolts all the way.

The installation must be carried out strictly following the instructions. Only in this case can the long-term operation of the transmission be guaranteed. Accelerators are mounted on some high-speed bikes.

Upset rear derailleur

Why does the chain on a bicycle skip at all under load? It either jumps over the stars due to insufficient frictional force, or it got between the sprockets, where there is no hook at all.

Frictional imbalance can result from a reduction in the number of contact pairs “cassette tooth-chain link”. This is influenced by the position of the chain tension adjusting screw located on the rear derailleur. By turning this bolt, you can move the frame up or down.

From personal experience. The chain tension adjustment screw is normally used once when installing a new derailleur. During the adjustment, this bolt, like L, H, is not touched.

What to do if the bike chain falls off?

Why the chain on a bicycle can fly off. an overview of the causes and their elimination

Thousands of new members are added to the cyclist army every year. Novice owners often do not know what causes the chain on a bicycle to fly off and what to do in such situations. Let’s consider the main causes of the problem.

Loose chain tension on bicycles without gears

The rear fork of a conventional bicycle, without shifting speeds, changes its position relative to the axis of the rear hub under the action of loads and vibration. Chain drive slack increases. A slight push releases the chain from the sprocket teeth. The chain slips off. To fix the problem, you need to follow the steps in sequence:

  • Flip the bike.
  • Loosen tensioning bolts.
  • Set the wheel to the required depth.
  • Tighten the bolts firmly in the new location.

You will enjoy cycling and the chain will no longer fly off if you set the wheel properly. Correct position implies:

  • lowering of the chain by about 5 mm. the “in line” state makes it difficult to spin the pedals;
  • the axle of the rear wheel hub must be perpendicular to the plane of the frame. Otherwise, the risk of deformation of the rim increases;

To improve the grip of the nuts, lock washers should be used.

If critical slack is not eliminated in the extreme position of the sprocket, you need to rivet the links to reduce the length of the chain.

Insufficient chain tension on shifter bikes

Often the reason why the chain flies on a high-speed bike lies in the fact that the compensating spring does not perform its functions to prevent sagging. Occurs when the spring is loose or the chain is stretched. If the check shows excessive chain elongation, you need to remove the extra links. A weakened spring cannot be repaired, you will have to change the rear gearshift block.

It happens that the chain comes off a bike with an incorrectly adjusted front or rear derailleur.

Adjustable by bolts with indexes “H” or “L”.

  • The chain will not fly off the rear wheel cassette if the derailleur sprockets are in the same plane as the largest or smallest sprocket in the cassette. Bolt “H” changes alignment with the smallest, and bolt “L” with the largest diameter stars.
  • For the front wheel, bolts “H” or “L” set the gap between the teeth of the stars and the walls of the front derailleur frame equal to one millimeter. Adjuster with the letter “L” sets the gap between the largest star and the inner wall of the frame, and with the letter “H”. between the smallest star and the outer side of the limiter.

You need to carry out the action with the gearshift unit with the setting on the shifter of the speed mode corresponding to the selected star.

Sometimes the chain on a bicycle flies off when the teeth are deformed from an impact or fall. In such cases, it is very difficult to return the teeth to their previous position on their own. Depending on the fastening of the stars on the cassette, a separate damaged star or the entire block changes.

Violation of the geometry of the bike frame or wheel (figure eight) can lead to unbalance and slipping of the chain from the star.

The cause of the breakdown is the change in direction of the carriage and bushing axes. As a result, the chain links do not fit tightly enough to the teeth of the sprocket and easily jump off. An additional negative manifestation of the deformation of individual parts of the bicycle is the accelerated wear of moving parts.

An insignificant “eight” can be corrected at home by loosening or tightening the knitting needles. Riding with a deformed wheel is possible, but you should remember that a rock or pothole increases the figure eight and the chance that the chain on the bike will come off. It is best to contact a repair shop, where they will explain to you why the chain on the bike flies and solve the problem with the breakdown.

Bicycle pedals spin or chain flies

If your pedals start to spin while riding, this can happen either as a result of wear on some parts of the bike or in case of improper care of them. So, what should you pay special attention to if you have such a problem:

  • articles:
  • your drive sprocket or rear sprocket is worn out
  • you have problems with the bike chain
  • you have problems with the rear wheel hub, ratchet
  • Find out also which pedals can be put on the bike and why you need it.

Bicycle sprocket crank wear

Bicycle sprocket problems can be seen with the naked eye. If you apply too much force to the pedals of your bike while riding, this can lead to a number of problems over time. For example, a bicycle chain is stretched and then you will have to change the bicycle chain

There may be another option that the sprockets on the bike wear off (lick off over time) and, as a result, poor grip, which leads to pedaling while riding.

It is quite possible that your asterisk is just dirty and it will be enough just to rinse it thoroughly from dirt, and then wipe it with kerosene to remove excess impurities.

If you have a problem with a licked asterisk. Then you will first need to remove the rear sprocket, and then disassemble it and possibly replace some parts with new ones, or maybe sharpen the teeth of the sprockets. It is better to give it to a professional for study. in a service center, or even better to replace the drive mechanisms by buying new parts instead of old ones, because how long they will most likely not last after repair.

Rear ratchet problems

a malfunctioning ratchet can also cause pedaling to spin. Perhaps too thick oil was poured into the ratchet and the bearings inside began to stick. Perhaps there is no oil at all and the mechanism is rusted, it is possible that the lubricant inside is mixed with dust and dirt, i.e. the grease has become patchy. The ratchet bearings may have fallen off. In this case, remove the bike ratchet, clean it, if necessary, from dirt (until it is completely cleaned), and then lubricate it with thick oil.

It is imperative to check whether anything needs to be lubricated at all. When you removed the ratchet, look at the color of the oil, if it is black or, so to speak, dirty or with an admixture of metal (bearing flew). in these cases, we clean and lubricate. Check if all bearings are in place. It so happens that a bearing breaks over time. this must be replaced with a new one. Also, when you look inside the cassette, make sure that there is no liquid inside. If there is still liquid, we clean and then lubricate. So, to summarize, if you look inside the ratchet (or cassette) and see clean oil, the bearings are in place, there is no liquid. in this case, do not touch anything. the bicycle chain lubrication and cleaning are simply not needed.

Bicycle chain problems

The chain is also subject to wear over time, and if your chain flies while driving, it may be stretched and needs to be replaced. Although things may be much simpler. It may be sufficient to rinse it out of dirt with water, and then lubricate it well.

, dripping one drop of oil for each link. A characteristic sign of a poorly lubricated chain in this case can be a squeak when driving, pedals spin poorly and you have to make significant efforts. Don’t force the bike, just lubricate the chain with oil.

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Then there is such a situation. Personally, I met with the replacement of the chain.

The chain was stretched and replaced with a new one. So, at that moment, I drove about a couple of years of intensive riding, and of course the chain and sprockets came into a state of slight wear. I replaced the chain, but when I put a new one everything was fine, until I got caught in the rain and in very heavy mud. From that moment on, the chain began to slip on the bike. I cleaned the bike pretty well and oiled it well. Although this had never happened before, no matter how mud I rolled, there was no scrolling. Well, it turns out there is such a necessity (feature) as “aging of the chain”, ie. the chain was too new for my rear sprocket, and therefore I just need to wait for it (chain) to age. In a simple way, you need to go and wait until the chain is rubbed with an asterisk. In this case, the problem arose only when the bike fell into the mud.

Ideally, the entire transmission of the bike should be changed. The transmission in this case is the entire mechanism leading to the movement of the bicycle. stars, chain, cassette (rear set of stars). If the chain is old, then it leads to wear on the stars. If the stars are erased, they will lead to a gradual deterioration in the state of the chain.

Also, chain slip problems can be caused by a jammed link. Those. some link does not bend softly enough, roughly speaking, it is bent in one direction or at the wrong angle. In this case, you need to bend the link into place or, as an option, bite it out of the chain.

How to quickly and conveniently clean the chain.

Now you know how to fix bike chain wear with your own hands. With the replacement of the necessary functional elements and the correct adjustment of the switches, the bike will ride like new again, delighting its owner with excellent speed and transmission on any part of the route.

The details of any mobile mechanisms, during their service, have the properties of being erased and becoming unusable for work. On a bicycle, these parts include: front and rear sprockets (cassette), bicycle chain and other mechanisms. Each unit in any technique requires proper maintenance, this makes the parts work out their resource and contributes to reliability and long service.

But still, how not to care for the bicycle chain, there comes a time when it starts to slip, time and load gives its own. In such cases, do not pull to replace the chain, as this may damage the sprockets on the cassette and pedals.

First of all, you should make sure that the front and rear derailleurs are set correctly. First of all, you need to pay attention to the hit of the chain on the sprockets and whether to lie between them. If the bike is not fast and has no derailleurs, then the first cause of chain slipping is loosening. In this case, it is necessary to tighten it.

If the switches are set correctly, and the circuit begins to slip under load, there are several reasons for this:

  • the chain is too stretched
  • front sprocket wear
  • wear of the sprockets on the cassette
  • or all of the above at once

Since when cycling, the chain inevitably stretches over time, the chain links no longer fit correctly on the teeth of the front and rear sprockets, and begin to wear them over time. The wear of the stars also occurs from the contamination of mechanisms with dust and dirt, so the chain must be periodically washed and lubricated. Read about how to do this in the article.

What to do if the chain starts to slip on the bike?

If, nevertheless, if your bike is already starting to overshoot syndromes, then you need to prepare to replace the chain and sprockets. Get ready immediately for changing the chain and cassette, as the already stretched chain

could easily damage its teeth, it may be necessary to change the chainrings too, it is necessary to watch their wear.

In some cases, you can postpone the purchase of stars. It is necessary to take a close look at the teeth, as a rule, it happens that cyclists prefer to ride at several speeds, while others only use a small amount of time. After looking at the wear, try not to switch to the speed at which the maximum output, use other stars. But this is still not a long way out of the situation, it is better to replace the necessary element, and boldly ride, not forgetting to service it, clean it, lubricate it on time.

Consider a common mistake made by beginner cycling enthusiasts. chain skew due to incorrect gear selection. In this situation, not only the chain, but also the front and rear sprockets, wear out strongly. The rule of gear shifting must be observed. For example, if the chain is on the front largest sprocket, then on the back you need to choose small ones. 1, 2, 3 stars.

For example, you should not go uphill in heavy gears (large sprocket in front, small ones in the rear), since the load also strongly affects the stretching of the chain and wear of the sprockets, and besides, it is easier to change the correct gear and calmly continue driving with ease.

Check regularly that the gear derailleurs are set correctly, as they can also cause chain distortion and wear on the sprockets.

Deformation of one or more teeth in the chainring or chainring

Why can the teeth warp? The first obvious reason is due to impact, the second is due to severe wear. In any case, if the chain falls off solely due to problems with the teeth of the cassette, then it is necessary to replace it with another one.

Weak tension

If your chain goes off on a bike without gears, all you need to do is unscrew the two nuts on the rear wheel axle and then pull it towards you. Tighten the nuts, but make sure that the wheel does not move closer to the center of the frame. By following these steps, you will see that the chain will not sag. Accordingly, the likelihood that it flies again is completely excluded. But in the case of the occurrence of this problem on a high-speed bike, you will have to sweat. A special spring is installed in the gear selector, which automatically pulls the chain. With prolonged use, it loses its elasticity, which leads to similar problems. Since the transmission is not separable, you will have to change the switch to a new one.

The chain is stretched due to prolonged use

This happens in the process of wear and tear. The switch spring cannot tension it normally, it constantly sags. In this case, there is only one way out. to replace the circuit with a new one. In practice, it is rare to find bicycles in which the chain is stretched and bounced when shifting gears. It is virtually impossible to restore its elasticity.

What to do if the bike chain falls off?

During the operation of the bicycle, the owner has to deal with a situation where the chain comes off during the ride. This situation is dangerous when driving at high speed, as well as in the process of screwing down a hill. Even if you use slip-on pedals with shoes to keep your foot from flying off the pedal, when the chain falls off, the cyclist can sprint over the handlebars or fall on his side. In this article, we will look at the main reasons why the bike chain flies, and also give practical advice on how to fix this breakdown.

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There are a number of reasons why the chain fails. They are listed below:

  • weak tension (applies to both bicycles without gears and with variable transmission);
  • curvature of one or more links;
  • deformation of one or more teeth in the chainring or chainring;
  • the chain is stretched as a result of prolonged use;
  • front or rear derailleur incorrectly.

Now let’s take a closer look at each problem. Here we will also offer solutions to emerging difficulties.

Curvature of one or more links

Such a problem can be encountered quite rarely, but it can still bother you at any time. If you notice that the links are curved, you have two options. The first is to completely replace the chain. The second is to get rid of the bent links using a special squeeze. Do not use this method on bicycles without variable transmission. On models with gear derailleurs, it is recommended to use this method as a temporary solution.

Front or rear derailleur incorrectly configured

This only happens on bicycles with gears. All you have to do is adjust the rear derailleur as precisely as possible. The problem is quite simple to notice: the chain can randomly jump to another gear during the pedaling process with great force, but at the same time you will not press on the shifter petal. There are two bolts on the switch body, with which you need to adjust the travel limit of the mechanism.

If you see that your chain is falling off, this does not always mean that you need to change it entirely. It is possible that the problem lies elsewhere. If you do not want it to fly off at the most inopportune moment, we recommend that you carry out maintenance from time to time. Check the transmission very carefully for wear. A simple check before driving will help you avoid serious injury, especially if you prefer to ride in an aggressive or even extreme style. We hope the tips above will help you avoid future breakdowns.