X-ring chain

An X-ring chain is a sealed roller chain in which rubber seals with an X-shaped cross-section sit between the inner and outer side plates. The seals keep factory grease inside the pins and bushes and stop water and grit getting in, just like an O-ring chain.

The X shape touches the plates on four small lips instead of one round surface, which reduces friction and power loss and lets the seal keep working better as the chain flexes. Similar designs are sold under names such as Z-ring or XW-ring.

Care: clean the chain with a cleaner that is safe for seals, never with petrol or a stiff wire brush, lubricate it regularly with chain lube, and keep the slack within the manual's limits. Replace chain and sprockets together when worn.