Question: what is the difference between o and x ring chains?
Answer: In an O-ring chain, a standard O-ring is used — essentially a tiny donut-shaped seal. An X-ring seal is a type of O-ring, but has an X-shaped cross section rather than circular. ... An X-ring also distorts less than a standard O-ring, and the gap between the sealing surfaces does a better job of retaining grease.