Chain: with or without O-rings?

While early motorbike chains were offered without O-rings, most motorbikes are now equipped with O-ring chains.

What are the differences between these types of motorbike chains?

O-ring chain

An O-ring chain consists of O-rings placed between the outer and inner chainrings of the motorbike chain to maintain lubrication between these components. 

Without these O-rings, this lubrication can quickly disappear (due to high speed running, lack of maintenance or simply over time); the contact surfaces will therefore overheat, deform, produce significant friction and eventually cease to function.

These motorbike chains with O-rings therefore prevent these risks by ensuring continuous lubrication, silent and efficient power transfer, protection against impurities that may slip into the plates and therefore offer a much longer life than a motorbike chain without O-rings. Please note that this does not mean that you do not need to regularly maintain the external pins of your motorbike chain using chain cleaners and sprays.)

This type of chain is most commonly used for sport bikes, large bikes and enduro bikes.

The downside is that these O-ring chains cause friction that can reduce the performance of the motorbike (the joints rub between the inner and outer links of the chain, slowing down the movement of the pins).

However, factories have developed different types of O-rings to counteract this disadvantage. For example, the RK factory has developed two types of O-ring chains:

* O-ring chains designed to give the motorbike chain an optimal life span: the seals are O'Ring ("traditional" perfectly round seals - such as RK SO series chains), RX'Ring (such as RK XSO series chains) or XW'Ring (such as RK ZXW, GXW and EXW series chains) - more advanced seals than O'Ring - with convex and concave features that trap lubrication and better isolate the chain's internal components from dirt and debris);

* Chains with O-rings designed for use in competition, minimising friction and power loss: the joints are U'Ring (RK MRU and HRU series chains) and UW'Ring (RK UWR and MXU series chains) which are ultra-thin joints.

Motorbike chain without O-rings

A "standard" motorbike chain without O-rings is lighter than a chain without O-rings and, due to the lack of friction from the O-rings, will perform better. If the chain is well maintained, it will give efficient results. This type of chain is most often used in competition (especially motocross) where the life of the chain is less important than for a road chain) or for small motorcycles/scooters.