A bicycle chain, front sprocket or system, rear sprocket or cassette form the bike’s drivetrain. A bicycle chain is made up of links. Many bicycle chain manufacturers supply their chains with a special detachable link. the chain lock.
The bike chain is subject to fairly intense wear and therefore can well be classified as a consumable. To extend the life of the drivetrain, cyclists practice using not one, but several chains, which are installed on a bicycle in a circular manner. Circular replacement usually requires 2-3 chains.
Bicycle chain main dimensions
Bicycle chain width or pin length
The overall width of the bike chain is determined by the pin size. The designers design the width of the bicycle chain based on the width of the cassette and the number of stars in it.
There is a clear trend towards a decrease in the width of bicycle chains with a simultaneous increase in the number of stars in the cassette.
Bicycle chain pitch
As noted, bike chain pitch is 1/2 ”or 12.7mm.
The number of links in the bicycle chain and its working length
The length of a bicycle chain is determined by the number of links that make up the chain. For example, spare parts chains designed to work with a 12-speed cassette are 126 alternating inner and outer links in length.
For a complete set of bicycles, chains are supplied in lengths of 108, 110, 112, 114, 116, 118, 120, 122, 124, 126 links.
Bicycle chains that come with parts are usually 114 or 116 links. The number of links depends on the manufacturer’s approach. Many bicycle chain manufacturers supply their chains with a special detachable link. the chain lock.
The number of links 114 or 116 may be excessive. Different types of bicycles require different working chain lengths. The working length of the chain is achieved by removing excess links.
For MTB mountain bikes, the chain usually has to be shortened to 106-108 links. This chain length is due to the size of the stars of the system and the length of the back feathers.
For bicycles with long rear stays, such as some 29ers, the chain is shortened to 112 links.
For certain types of bicycles, such as road bikes, the chain can be omitted and used out of the box.
When replacing the factory chain with a new chain, be sure to calculate and record the number of links in the factory chain. In new chains, if necessary, leave the same number of links as the factory chain.
For road bikes, the size of the chain is usually not changed. boxed versions are suitable for them. However, the number of links in the chain purchased must still be recalculated. As a rule, it is better to determine the length by ordinary visual calculation or look in the product passport. For road bikes, the number of links ranges from 114 to 116.
When adjusting, the chain on the bike is installed on the large gear in front and the small rear. The calculation of the drive length is selected in such a way that the rear axle of the wheel and the axles of both tensioners are in the vertical plane.
Single speed models are the easiest to adjust. The bicycle chain is selected so that the axle of the rear wheel is in the cutouts of the bicycle frame, and then has the ability to move when pulling the chain drive during operation. Some users install a “half-link” chain for more accurate positioning. She has an odd number of links, which greatly simplifies the task.
On road bike models, the number of links also varies from 114 to 116 pieces.
Take the survey
It is important to pay attention to the nearest connecting rivet, since the connection occurs only by crossing the outer and inner plates.
The second method of measurement is along the existing chain. Experienced cyclists advise against immediately throwing out the old chain, as it may be needed to select a new product. To do this, cut the new chain to the same length as the old one. Then you need to set the gear speeds so that the chain is on the smallest sprockets at the front and back. There should be no noticeable sagging of the bike chain when the tensioner foot is in operation. At the same time, it should not touch the upper part of the pulley.
A slight slack should be present. a strong one indicates an excessive length of the chain drive.
In this case, they find a rivet touching the star, mark the star in this place with chalk. Count a couple of rivets towards the derailleur and pull the bike chain up to the mark on the sprocket, lifting it up. The chain has been shortened. After another check and reduction by a multiple of the number of rivets, the bicycle chain should be reduced, the sagging should disappear. It may now be shorter. This is checked by shifting to the largest front gear and the second largest rear gear. The drive should not be too tight and there should be a double bend in the pulley wheels. After that, a couple of links of the new chain should be returned back.
If the chain fails both tests at once, then the switch capabilities are not matched to the transmission capabilities. The length needs to be adjusted to fit through the largest sprockets at the back and front.
How to Count Motorcycle Chain Length for Honda CB350 CB360 CB450
If the old bike chain is the correct length, then the new one is measured according to the length of the old one. To do this, you need to put it on a flat surface, straighten it. The chain must be aligned with the vertical rollers. The new chain is placed side by side. The ends must match, taking into account the presence or absence of rivets. The links of the old product are shifted to the position that coincides with the new one. After that, you need to inspect the correspondence of the chains, taking into account the presence, location of the rivets. Trim new product.
There is also a method for determining the length through mathematical models. For bicycles with a large sprocket difference, the equation will be quite complicated. Therefore, this method is rarely used.
New links should not be added to an old bike chain. It is useless as it is already stretched, badly worn out.
How To Calculate The Correct Chain Length | Road Bike Maintenance
A slight slack in the chain drive is considered acceptable, and a strong one indicates its excessive length Experienced cyclists do not recommend throwing out the old chain, as it can be useful for choosing a new product It is highly undesirable to add new links to an old, stretched and worn bike chain
The simplest gear of this 1-speed city bike allows you to do without maintenance for a long time. This device is suitable for leisurely trips in city mode for people who do not want to go into the intricacies of bicycle mechanics. Most singlespeeds are equipped with a dependent hub, so the bicycle pedals are constantly in motion. Some models are equipped with a ratchet, which allows you to interrupt the movement of the pedals during the stroke.
The tight chain tension ensures a slip-free movement. The chains for this transport are thicker and do not require frequent replacement. If the chain is changed to a new one, then it is successfully rubbed against the worn parts of the rear gear and sprocket. The length is calculated in the same way as for other models. The disadvantage of this type of transport is the lack of gear changes. when driving uphill, great muscle efforts are required.
Single speed chains are thicker and do not require frequent replacement
Basic sizing methods
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 install 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 of 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 junction area, which must be removed.
It should be further noted that in determining the optimal length of the 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 degree of reliability of the bicycle chain will significantly decrease.
For singlespeed (single speed bike)
To choose 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 the original.
Single speed bike chain length
To determine the chain length for a single-speed bicycle or a bicycle with a planetary hub, it is enough to install the hub in the frame dropouts so that it can be further pushed back as the chain stretches.
I installed my planetary hub almost at the beginning of the dropout so I could move it back.
Road bike chain length
For road bikes, there are usually 3 ways to determine chain length. This is a method in which the chain is placed on a large chainring and a small rear.
Checking if the bike chain is too long
After you have chosen the chain length as described above, I recommend that you test the chain operation when using the two smallest chainrings at the front and back. If the foot is almost parallel to the ground, your chain is too long. It will likely jump off bumps frequently (as the switch will not be able to pull it properly). The foot should be at a slight angle. See the photo below for more details:
As you can see in the photo, the foot is set at an angle. This means the chain is tensioned by the derailleur and is the correct length.
The recommended distance from the top roller to the chain is 2.5 to 4.5 cm.In this case, the derailleur will work correctly.
I got about 2.5 here, since this bike has a very large 1 star on the cassette.
Lightweight bike chains
They can be for both single-speed and multi-speed bikes. The main difference is the empty pins and the presence of holes in the plates. This makes them lighter than their counterparts by about 20-25 percent. Typically these chains are used by riders in disciplines where every gram counts. Lightweight bike chains stretch, wear and tear the fastest due to their nature.
The main parameters of the bicycle chain
A bicycle chain is made up of links. In the English literature, the term link is used for this. English. Link. link, links. links.
Bicycle chain links are different. The standard distinguishes between inner link, outer link, connecting link (chain lock) see Fig. 1.
Bicycle chain manufacturers rank them in terms of reliability, precision and durability.
Modern bicycle chains can be used equally well on various types of bicycles. A bike chain can be used on a city bike, road bike, touring bike, or mountain bike. However, some manufacturers clearly relate their bike chains to bike types.
The bike chain has been re-configured for smoother gear shifting. In some areas of the plates, the designers provide special chamfers. These chamfers facilitate the operation of the shifters by speeding up the secure engagement of the sprocket teeth and bike chain see Figure 2.
Chain wear depends on operating conditions and regular maintenance. Due to different operating conditions, identical chains from the same manufacturer installed on a mountain bike and a road bike will wear differently.
Let’s analyze the main parameters of the bicycle chain, which play an important role in the selection of a new chain.
A special species that differs in its structure. This chain has no internal or external links, but consists of repeating elements. Can be used on single-speed and multi-speed bike.
Of the advantages, one can single out the fact that it is much easier to fit them to the required size of the bike. But of the minuses, this is not the perfection of the design, in which the base stretches and wears out very quickly.
How long should the bike chain be?
I think many who change chains on their own bike ask themselves the question: “What should be the correct chain length?”, Since new chains come with a margin in length. And, of course, the simplest thing we can do is count the number of links on the old chain and leave the same number on the new one.
But what if you are not only installing a new chain, but also changing the cassette or installing a system with a different number of stars? The chain length will change, and the old chain is no longer a helper. Then you should use these 3 methods to calculate the length of the bicycle chain, and no calculator is required for this: