Spins the chain on the bike under load

“Chain damper

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.

Spontaneous gear shifting

Spontaneous gear shifting occurs in the same way as overshoot, but only after it the chain is on another smaller sprocket (higher gear). The reason for this is the sum of two reasons. the flexibility of the frame and the friction of the cables.

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.


So what to do if a chain slips on a bike under load? The easiest option is to completely replace the transmission. However, it is not necessary to do this, you can determine the most worn out part of the system and repair only it.

It is necessary to change the stars only in extreme cases. However, this is a temporary solution. Eliminate the cause of the malfunction. replace, shorten the chain or adjust the switch.

Depending on the degree of wear of the part, the following repair methods are used:

  • complete replacement. in this case, breakthroughs can happen even more often at first, but over time, the parts will get worn, and the problem will be eliminated (while you do not forget the unit so that it does not work for wear);
  • shortening. several links are removed using a squeeze;
  • use. a device that increases the tension of the chain using rollers, preventing it from jumping off the sprockets.

Important! If there is no strong wear, but the chain still slips on the bike, you need to set the tensioner in the correct position and adjust the tension of the cables.

How to troubleshoot a bike chain malfunction

Why does the chain slip on a bicycle under load

Sometimes bicycle pedals will slip, especially when a lot of force is applied to them. This phenomenon is even more common when the cyclist stands on the pedals. To avoid chain slipping, the rider has to downshift and stay in the saddle instead of standing in higher gears.

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Very often the switch is blamed for slipping and jumping the chain, as well as spontaneous gear shifting, but the phenomena that were listed above are very rarely caused by its improper operation.

How to fix a slipping skipping chain bike during pedaling problem solved

Why the bike chain can slip

To have an idea of ​​why a transmission fails, you need to know its structure. It consists of chainrings, a cassette on the rear wheel and a chain that connects these two groups of parts into a single mechanism. It is thanks to this device that the transmission receives the cyclist’s energy, transfers it to the rear wheel, which ensures the movement of the iron horse.

Heavy wear on the mechanism leads to chain slippage on the bike. This problem increases the accident rate of the vehicle. Riding a high-speed bike with this problem is traumatic and uncomfortable.

Downhill movement is especially problematic. Under maximum load, the transmission simply stops working, and it turns out that the pedals are spinning, but the bike does not move. There are several reasons leading to a breakdown. Among them are the following:

chain, bike, load
  • Thinning of chain links and, as a result, its lengthening;
  • The wear of sprockets and cassettes, determined as the teeth become thinner, the degree of which is quite realistic to reveal simply by eye;
  • The presence of both reasons at the same time.

Transmission diagnostics is carried out using a special tool, which is a ruler of a certain type or a special caliber.

If the bike breaks down somewhere on the road, then the cause of the breakdown can be identified in a very simple way. To do this, you need to throw the chain onto the largest star of the system and pull it back by grabbing one of the links with your finger. In the event that it rises above the star to the floor of the tooth, it must be changed. If it turns out to be delayed even more, then it’s time to replace the cassette on the rear wheel.

As you know, the chain length in the normal state is 304.8 mm. Its deformation towards elongation contributes to a strong effect on the teeth of the stars, as a result they become thinner. In this case, the process begins on small, and then goes on to large elements of the star system.

This greatly reduces the efficiency a speed bike provides for gear shifting. Transition to higher speeds becomes especially problematic.

Improper shifting is another reason a transmission fails much faster. In this case, an extremely high chain misalignment occurs and all parts included in the articulation experience tremendous wear.

Cyclists who are well aware of all the nuances of this type of transport know that a high-quality chain slips, but only if it has traveled more than 3000 km. One cassette can survive two or even three chains.

At least three chains are in good working order and star systems. The transmission is affected by the conditions of use of the bike and timely measures for its maintenance.

How to fix the situation?

Here you need to start from the root cause. If the wear of the transmission is noticeable on the face, then only change it. In this case, all consumables are subject to replacement: chain, cassette and stars on the system. Only the most experienced cyclist can tell if the sprockets are suitable for future use. Needless to say, the use of old and new parts together will inevitably lead to their rapid wear? Better to change the entire transmission assembly.

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But it also happens that the chain does not seem to be old and looks decent, but it still slips under load. Here you need to understand that the algorithm for fixing the problem on a high-speed bike is a little more complicated. To eliminate one of the common causes (stretching), you need to focus on its standard length.

Installing a damper

When the chain slips on the bike under load at certain speeds, you can install a damper. This is a special device equipped with plastic parts that protects the stars from mechanical damage (driving on curbs, pits, etc.) Installation algorithm:

  • Remove the stars and connecting rods. In this case, the largest should be on the middle.
  • Tighten the rockring and 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.
  • Place a drop of threaded rods in the area between the fastening bolts.
  • Install connecting rods.
  • Put the stars on the chain.
  • Fasten the rollers.
  • Align the distance between the inner pancake and the star so that it coincides with the same indicator, only between the outer.
  • Tighten the bolts until they stop.

This should fix the problem. What to do if the chain slips under load anyway? If the new transmission and installation of the damper did not solve the problem, then you need to see if the rear derailleur is correctly set.

How To Fix Gears Slipping, Skipping And Jumping Under Load

Eliminate chain slippage under load

Never trust people who say something like, “I’ve been skating for a year now and haven’t changed anything.” And even more so, do not repeat their mistakes. A bicycle is the same transport that needs competent, and most importantly, timely maintenance. Every detail and every knot are closely related elements that ensure a comfortable ride. In carrying out its work, the bicycle experiences significant loads that are distributed between the mechanisms. And most of all goes to the transmission. Lack of attention to this knot leads to tangible problems: at the most inopportune moment the chain slips on the bicycle under load, for example.

Needless to say, this creates significant discomfort while driving? But that’s not all: following the chain slippage, other problems begin, which can ultimately lead to a complete replacement of the transmission unit. We will analyze why this happens and how to fix the situation, and also talk about how to prevent chain slip under load.

How chain length affects transmission performance?

Armed with a tape measure, we measure the length of the chain. Normally, this figure should be in the range of 304.8. 306.4 mm. If the length exceeds the threshold, you can judge the elongation of the chain. over, the longer its length becomes, the more unbearable it is to ride a bicycle. Enterprising guys artificially shorten the length by squeezing out several links. This solves the problem, but only for a while. Ultimately, the chain will still have to be changed.

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How to fix the problem

If the chain is worn out, feel free to buy a new kit. Inspect the parts carefully for deformation before purchasing. And remember you are finally simple rules:

  • One cassette is enough for 3 timely chain changes.
  • The lifespan of a star is 10-15 thousand km.

And now, in fact, you can start replacing the chain. The main thing is not to rush and strictly follow the instructions.

Possible reasons

As they say, you love to ride. love and follow the technique. This truth is as old as the world, but for some reason many people ignore it: after riding in the mud or in the rain, they leave the bike unattended, and the next day they sit on it as if nothing had happened. But this is for the time being, because sooner or later the owner will not only notice, but also hear that the chain slips on the bike under load. Why is this happening? The reasons are ridiculously small. One of the most common is lack of attention to technique. Dirt, sand, water, rust build up over time on the transmission, making it difficult to operate. This is especially noticeable when going uphill: you make an effort by turning the pedals, and at a certain moment the chain slips, which is accompanied by an extremely unpleasant sound.

If you are not keeping an eye on the transmission, then the reason is obvious: it’s time to clean and lubricate the chain. But there are other factors that cause the chain on a mountain bike to slip under load. Let’s analyze them.

Chain stretching

A bicycle, like a car, has its own consumables that are designed for a certain service life. The number and size of links are carefully calculated by engineers and checked during production. But, as they say, water and stone wears away. Over time, with regular and intense loads, the teeth of the chain can wear off, which leads to the stretching of the chain and, as a result, its slippage.

Here you need to focus on the established standards. For example, the length of a mountain bike chain is 304.8 mm. Unfortunately, it will not be possible to tighten or fix it in another way: only a replacement.

Step by step replacement

A special tool will come in handy here. squeeze. You need to lay a link on it so that the pin is exactly in front of the axis. To squeeze out a pin, you have to sweat: scroll slowly the knob and stand just before squeezing it out.

The new chain can now be put on, starting by engaging the derailleurs on the small sprockets, taking into account the position of the rollers. It remains only to combine the links, clamp the chain and press the axle.