Seals for Motorcycles

March 3, 2016 – by Eastern Seals

O-rings and X-rings for motorcycles.

Let’s face it, without a chain, your motorbike isn’t going anywhere. So why, then, do chains get ignored for so long? Chains have improved so much over the years that it is easy to forget about them. Prevention is far better than cure.

There are really two main types of chains: O-Ring chains and Non-O-Ring chains. O-Ring chains have small O-Rings built into them. The O-Rings are used to keep grease and lube inside the chain (between all the moving parts). The non O- Ring types date back to the beginning of time and are still used 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.

What are O Ring and X Ring chains?

As motorcycle technology and power output has increased, chain design has had to improve with it. So for larger and more powerful motorcycles, non O-Ring chains have been very much superseded by O-Ring and X-Ring chains.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 for motorcycles!

Eastern Seals can supply virtually any size of X-Ring or O-ring, and in a wide range of materials. We also offer a free parts identification service, so if you are not 100% sure on your requirements, our technical team can help.

Need to repair your engine?

During a motorcycle engine rebuild, it is good practice to replace most of the bearings and all of the oil seals.

Most bearings inside an engine are of the ball or roller type and with correct lubrication will last many hours or miles. However, crank bearings – especially on 2-strokes, are subject to high stresses, and if the engine is being rebuilt / refreshed it is an ideal time to replace them. Oil seals are relatively inexpensive and should never be reused.

Whatever engine oil-seal you need, we can supply it. Crankshaft Oil-Seals, Layshaft (sprocket) Oil-Seal, Gear Change Shaft Oil-Seal, Water Pump Oil-Seal, Clutch Actuating Shaft Seal, Kick and Starter Shaft Oil-seals… contact us for more details, or to discuss your application.