Currently, mainly 3 types of chains are installed in motorcycles. In addition to the timing belt and the cardan shaft, the drive chain has been the most commonly used type of propulsion for decades. Reason enough to take a closer look at this essential part. After all, nothing runs without the chain!
To get through the confusion of designations and abbreviations (415S, 415ERZ, 420D, 420NZ3, 420V, 428HD, 428NZ, 428VX, 520 standard, 520MX, 520NZ, 520ATV2, 520ERV7, 520VX3, 520VR46 Rossi, 520ZVMX, 525VX3, 525VR46 Rossi, 525ZVMX, 530NZ, 530VX3, 530ZVMX and 630V), it is important to know the key facts. We'll break it down for you a bit:
Chain size - higher mathematics
Often referred to as chain type, 9 different drive chain sizes are considered common. These are installed in over 90% of motorcycles and are standardized according to a DIN. The respective size designation is composed of the roller diameter, the pitch and width of the chain rollers. But before we digress too deeply into the mathematics, let's keep in mind that only 2 chain sizes are used for 125cc motorcycles.
On the one hand, KTM uses a 520 chain on their 125cc Duke and RC models, as does Aprilia on their RX and SX models from 2008-2014. On the other hand, all the rest of the usual models, such as the Yamaha YZF-R and MT 125 or the Honda CB 125 R, all Kawasaki and Suzuki models, as well as Beta, Aprilia and Brixton use a 428 chain.
Chain length - easy going
Nevertheless, the chains are not completely universal to use. Because they differ in length. Fortunately, it is much easier to determine the length of a chain than the size. It is only necessary to be able to count to 140, because the length of a drive chain simply describes how many chain links are installed. Since the maximum for the axle-liters in their original state is 138, and one chain link is always marked, this is a task of a few minutes. KTM's chains include 112 links, Kawasaki and Yamaha up to 134 links depending on the year of manufacture, and Brixton's BX and Felsberg models 120 links.
It is quite easy to shorten chains but, without special tools, very difficult to lengthen them. For this reason, many of the chains in our store have a standard length of 138/140 links. So they can be used for almost any model.
Function - Riding a bicycle you do not forget
The function of a drive chain can also be explained in short words without delving too deeply into the mechanics and physics of an internal combustion engine. After all, it works just like riding a bicycle - power transmission.
The engine (in the case of a motorcycle) or our legs (in the case of a bicycle) set the front sprocket, on which the chain lies, in motion. The "teeth" of the sprocket pull the chain along. This in turn pulls the sprocket on the rear wheel along with it. Tada - the rear wheel turns and the bike/motorcycle moves forward.
If you want to know more, we have written an article here that explains the function of the chain and transmission in more detail.
Tensile strength - horsepower and driving style dependent
A chain must therefore withstand permanent pressure of up to 15 hp (the equivalent of 4,500 duckweights). Whether and how well it does this is expressed by the tensile strength. In the 125cc segment, values around 3,000 kg are already more than enough. This value results from the material, the sealing and the processing. Among other things, this value is also decisive for the price of a chain. For example, an AFAM chain recommended for touring costs up to several hundred euros for large BMW Tourers, but also has a tensile strength of over 4,100kg.
Sealing - xoxo
Not only bright colors and size distinguish chains from each other. Probably the greatest quality feature is the sealing. Because, what many do not know - The rollers of a chain must be permanently lubricated. To ensure this, greases or oils are included in the rollers - mostly - not in standard 125cc motorcycle chains... However, already a quality level above it is commonplace.
These oils and greases naturally escape over time, causing tensile strength to suffer. To slow down this process, sealing rings are installed. According to the shape of the cross-section of these sealing rings, they are called O-rings or X-rings. The O-rings use two contact surfaces to prevent dirt from entering between the links, and the permanent grease remains where it is. X-ring chains work on the same principle. The only difference is that the cross-section of the sealing rings is shaped like an "X" and thus they have four sealing contact surfaces to the outer and inner link plates. Since X-ring chains maintain the lubricity of the chain longer, they are also more durable than O-ring chains.
Mileage index
In the end, however, probably very few of you want to spend forever looking at a motorcycle chain and comparing all the data and quality levels. So there is a value that captures all these criteria and more in one number: The mileage index.
"The mileage index given by the motorcycle chain manufacturer DID indicates how high the mileage of the respective motorcycle chain is compared to the simple standard chain without seals and reinforcements. So the higher the mileage index, the higher the expected service life of the chain."
In the confusion of names and abbreviations
If you now take a look back at all the abbreviations from the first paragraph, some light will be shed on the subject. The numbers in front always indicate the chain size (usually 420, 428 or 520). This is usually followed by the chain name - e.g. "NZ" or "HD". Here the manufacturers are very imaginative.^^
Following the name is only the sealing - if you find an "X" in the designation, it means that the chain is compressed with X-rings. An O-ring compression is usually not specified in the name. If a number then follows, it is usually a much-used chain that has been further developed, such as the "525VX3".
Of course, there is much more to learn about the drive chain and its quality characteristics. However, the information presented should be enough to help you choose your next chain. If you have found a chain and need help installing it, take a look at our article here: "Chain replacement on the KTM Duke".