The Ritchey WCS Lower Headset Assembly IS42/30 is a premium-level headset component engineered for modern bicycles that use an **internal 42 mm headtube** and a **30 mm fork steer tube**. Part of Ritchey’s World Championship Series (WCS), this lower headset assembly delivers smooth steering, reliable bearing performance, and robust structural support — making it ideal for road, gravel, and mountain bikes where crisp handling and durability are priorities.

At the heart of this assembly is a high-quality sealed cartridge bearing designed to resist dirt, moisture, and contaminants that can degrade performance over time. The precision-machined cups and bearing interface ensure low-friction rotation and long service life, helping maintain confident steering feel mile after mile. The robust design also contributes to frame integrity by supporting the fork’s steer tube where it enters the headtube, reducing flex and maintaining alignment under load.

Installation is straightforward with standard press-fit tooling suited to the IS42 headtube specification. The WCS Lower Headset Assembly IS42/30 pairs seamlessly with matching upper headset components and other Ritchey WCS parts — offering a cohesive, high-performance cockpit foundation. Whether you’re refreshing worn bearings or building a new bike from the ground up, this assembly brings dependable performance backed by Ritchey’s reputation for quality and race-tested durability.