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.
4 Worst Mistakes In BICYCLE CHAIN Maintenance. How NOT to do it. SickBiker Tips.
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.
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.
Why does the chain fly off on a speed bike
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.
Old bike chain slips
She stretched out to a critical level. If you want to be sure. purchase one of the control devices and estimate the degree of elongation:
- Special chain gauge. The meter is simple and convenient.
- Calipers. From the point of view of accuracy, this tool is preferable to the caliber.
- Roulette. The most inaccurate device.
A bicycle, like a car, has its own consumables. This includes all the components of the chain drive. Why do chains 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.
The algorithm of actions when putting on the chain is approximately as follows.
- Turn the bike upside down, placing it on the saddle and handlebars, or lift it up so that the rear wheel rotates freely.
- If the bike has a bicycle chain guard, it is better to remove it. This will make it easier and more comfortable to reach the chainring. If you are too lazy to shoot, or you can already reach the asterisk. well, it’s your business.
- Place the chain completely over the rear sprocket. (If you have not removed the protection, then it may be more convenient to completely put it on the front sprocket).
- Place the chain over the chainring in the direction of rotation and pedal forward in the direction of travel. When the pedals are rotated, it itself is thrown over the remaining teeth.
Here you need to understand that if the bike is upside down, then the chain is thrown onto the lower part of the sprocket (in relation to you) and, scrolling the sprocket itself by the pedal clockwise, we throw it on the front sprocket entirely. If you start to throw the chain over the top of the sprocket in relation to you, you will not be able to pedal. after all, in fact, you will have to press the brake.
If the bike is in the normal position (wheels down), then again throw the chain on top of the sprocket and pedal clockwise. as if you were driving forward.
Bicycle sprocket crank wear
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.
Bicycle chain problems
The chain is worn out, some links need to be bent
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.
Bicycle pedals spin or chain flies
The chain and cassettes must be kept intact
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:
- Find out also which pedals can be put on the bike and why you need it.
Rear ratchet problems
Malfunction of the ratchet under the cassette (or if the ratchet and cassette are one piece)
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.
Speed bike problem
For a regular bike, this problem is easy to solve, but what if the chain jumps off on a high-speed bike? Among the most common causes of this problem are the following:
Bicycle Chain Drop. How To Fix It On The Fly. Dos And DONT’S. Cycling Tips.
- deformation of one of the stars. Gear shifting on multi-speed bicycles is carried out using cassettes consisting of several stars. These designs are collapsible and non-collapsible. Replacement of a damaged sprocket is possible only in collapsible structures, if the structure is non-collapsible, its complete replacement is required.
- Mistakes in the setting of the derailleur can cause the chain to fly off the bike when shifting gears. Gear shifting should be fine-tuned. If the bike owner himself cannot do this, you need to contact a specialist, or carefully study the instructions for setting the bike speed switch. The safety of the cyclist depends on the quality of this function.
- Stretching the bike chain. This process is associated with long-term use of the chain, the application of high dynamic loads to it, irregular cleaning, due to which the residues of lubricants, mixed with dirt and dust, accumulate on the chain links. In this case, the chain must be shortened or replaced. To shorten the chain, you need to remove several links from it. This is done using a special squeeze tool. This simple tool is a must-have for every cycling enthusiast. With its help, the axle of the link (pin) in the lockless type bicycle chain is pushed out. If there is noticeable stretch on the bike chain, and the service life is long, it will be more advisable to replace it completely. To maintain the chain in good condition, it must be periodically rinsed in kerosene and cleaned.
- Curvature of individual chain links as a result of which the chain flies off the bike.
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.
How to increase the tightness of the bike chain on a single speed bike
So that the chain does not fly off again next time due to sagging, it is better to immediately increase its tension.
To do this: Loosen the nuts on the dropouts a little so that the rear wheel moves a little and pull it back. With the correct bike chain tension set, slowly tighten the nuts. Just do not skew the rear wheel and check that it rotates strictly in the vertical plane and does not touch the frame and wing feathers.
There is no need to tighten the bike chain too much, the pedals will spin tightly. There should be a slight slack, but a maximum of 1-1.5 cm.
If the rear wheel has nowhere else to move. remove one link.
Now about how to put the chain that has flown off on a single-speed bicycle into place.
The idea is this: First, it is completely put on one of the stars (usually on the back, but you can also on the front) and thrown over the second sprocket (front or, respectively, back) to lie on the part of the teeth. Further, when scrolling the pedals in the direction of travel, the chain is captured by the remaining teeth of the sprocket and completely lies on the entire sprocket and is thus put on.
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.
For example, here’s a video on setting up the rear derailleur on a bike.
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 sprockets;
- two reasons at the same time.
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.
The most common cause is that the chain is stretched due to prolonged use of the bike, as a result of which its components 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-out part. Therefore, there is only one way to solve the situation. replacing the chain.
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.
- 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 different grooves and pins with the same size on the bushing 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;
- alternately wear stars and spacer rings;
- some models of cassettes suggest 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 a cassette puller until it stops.
To eliminate the risk of 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 others.
How are ISCG dampers installed:
- prepare tools: hexagons, squeeze, carriage pullers, thread clamps, wrenches 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;
- with threaded fasteners dripping 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;
- then tighten the bolts all the way.
Measuring chain stretch
Stretching the chain does not imply its lengthening, 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 upper 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 the replacement of the chain 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 the 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.
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? The 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 lubrication. But even if all the rules for caring for the transmission are followed, its parts will still wear out over time. Then their replacement is required.