What’s the difference between O Ring and X Ring chains?
There are three principal types of roller drive chains: non O Ring, O Ring and X Ring. The non O Ring types date back to the beginning of time and are still used extensively today. They are strong, light, cheap to produce and relatively friction free but they do not have internal lubrication, so they tend to wear out more quickly. These days they tend to be used most on smaller capacity and Moto X bikes.
As motorcycle technology and power output has increased, chain design has had to improve with it. So for bigger and more powerful bikes, non O Ring chains have been very much superseded by O Ring and X Ring chains. These position a sealing ring between the inner and outer chain plates. Before riveting in the factory, the internal parts of the chain are filled with chain grease by vacuum. The sealing rings then have two purposes: to keep the internal lubrication in, and to keep the dirt out, thus vastly improving the durability of the chain. O rings were available first and the ring is literally O shaped. As the two plates push on either side of the O ring, it distorts to have two flat sides to its shape. This is great for sealing and great for most uses but it creates considerable friction which saps the bike’s power.
That in turn led to the development of X Ring chains. X describes the shape of the ring. Instead of having an O shape it now has an X shape. This means that when pressed between the chain plates, it no longer has a flattened O ring shape but instead has two smaller faces touching either plate in an X shape. This gives you the same great sealing and durability but now with very low friction. The perfect chain!