Bicycle chain length: how to determine and choose the best one?

Bicycle chain - links connected one by one with pins. It is intended to transmit torque. The efficiency is capable of reaching 98%. When mounting a new chain on a bicycle, as a rule, it is necessary to correctly calculate its length or the number of links. A short chain can lead to problems if gear changes are made to large sprockets. Too long chain - will sag and jump off the sprockets on its own.

There are two key tricks for determining a parameter such as chain length.

• The most important thing is to install it on a large sprocket in the transmission system, at the same time it is necessary to put it on the smallest sprocket in the rear sprocket system (also known as the rear cassette). Then you need to pass it through the rear derailer (this is the name of the derailleur). After completing this work, tension it so that the axle that passes through the center of the rear derailleur rollers is in an upright position. If the correct chain tension has been performed and it turns out to be longer, a certain amount of extra links will form at the connection section of the 2 ends. They can be easily removed by adjusting the chain length at the same time to fit your own bike.

• The next method actually mirrors the sequence of steps of the previous method. That is, mount the chain on the smallest sprocket in the transmission system and the same sprocket in the rear sprocket system.At the same time, there should be a slight tension on the chain, that is, the bike chain should not be loosened. It follows that unnecessary links may also remain in the joint area, which must be removed.

It should be additionally noted that When determining the optimal length of a bicycle chain, you can practice the first and second methods at the same time. If in both versions the same number of unnecessary links came out, then it means that you can safely remove them.

When the number is different, then it is worth checking again, since it may be that a mistake was made in some of the options. If you remove the wrong number of links, there is a risk of getting a chain that is too long or too short. In such situations, driving on two-wheeled vehicles is risky, and the reliability of the bicycle chain will be significantly reduced.

There are three main calculation methods, if we talk about mountain bikes and bicycle hybrids.

1. Place the chain over the largest sprockets at the back and front of the bike, Pull the leg of the rear derailer to the maximum, it is necessary that at the same time it moves forward - this will be the ideal size of the bicycle chain. It should look like this: the derailer's body will be practically in line with the paw (this is the maximum, further - failure). Please note that it is recommended to install the foot at a slight incline.
2. Just as in the previous version, the chain is thrown onto the largest sprockets without involving the rear derailer... We write down or remember the required chain size, then add a couple more links to this parameter, and an acceptable length comes out. In principle, the result should be approximately the same as in the first method.
3. Attach the chain at the front to the large chainring and to the smallest one at the back and adjust the size so that the derailer's foot is at right angles to the ground, that is, the axes of the derailer's rollers are located under each other.

For a road bike, the 3rd method is usually used for calculating the size of the bike chain. This is a technique where the chain is installed on a small sprocket at the back and a large sprocket at the front.

To select the length of the bicycle chain for a single speed or a bicycle equipped with a planetary hub, it is necessary to install the latter in the suspension bracket of the frame (dropout) so that in the future, as the bicycle chain is stretched, it will be possible to move it back.

Attention! When replacing a factory chain with a new one, it is imperative to count the links in the factory sample. In the new chain, if necessary, it is necessary to leave the same number of them as in the original.

There are two methods to count the number of links.

1. Count all the outer links together with the lock, and then multiply by 2. It is possible, of course, to count the inner links, but this is not very logical.
2. Count all pins (their number must match the number of links).

Choosing the right chain depends on how many sprockets you have on your bike. If it is equipped with 5, then with this option, a typical version with a width of 2.4 millimeters will be suitable. When the conversation is about a bicycle with 6-7 sprockets, then you should choose more expensive and high-quality products, since typical products may simply not tolerate such loads, not to mention the degree to which this process must be taken seriously when purchasing a chain for a bicycle with 8 stars, because only the most flexible and expensive samples can suit it.

Of course if desired, it is allowed to use cheaper analogs, but then you will have to replace them quite often, moreover, it will most likely be required to do this together with cassettes, which makes savings very unlikely.

Moreover, the parameters of your old and new chains must match one hundred percent, and especially this concerns their width.

It should be noted that individual samples are subject to additional marking according to the quality of their workmanship, and, as a rule, it comes in the form of numbers. Accordingly, the higher the number of the marking, the better the product. In addition, it should be said that chains often differ in their color, and the best samples are painted exclusively in the color of gold.

You can find out how to determine the length of a bicycle chain in the video below.