Freehub Kit ZR1 XD-R 12 Spd.

• Replacement freehub for Zipp ZR1 Hubs

Let’s start with bearing preload, a key factor in hub performance and durability. Zipp’s Cognition, ZR1, and ZM2 hubsets feature the automatic bearing preload for longer bearing life and easier serviceability.

Previous versions of Zipp hubs featured a set screw to adjust preload. While this system allowed riders to dial in their preferred preload, the Schweinfurt team developed a more precise and straightforward system for ensuring the correct preload: a precisely placed wave spring.

SRAM Senior Design Engineer Joachim Goebel explained: “The end cap has its end stop on the axle end and presses a wave spring against the inner ring of the non-drive side bearing, which provides the correct bearing preload automatically. If the bearings wear a little bit over time, the bearing play through time will be adjusted through the system automatically.”

The system is a user-friendly way of ensuring the right preload. “That little wave washer is doing a lot of good things for you,” Zipp Product Manager Bastien Donzé said. “It’s a critical piece of the design and why our hubs have improved so much in durability.”

SPOKES AND SEALS

Zipp hubs are designed for j-bend spokes, which are ideal for building durable wheels with consistent tension. J-bend spokes also are readily available and easier to service as a convenience to customers.

All steel bearings (carbon and stainless) used in Zipp hubs have the same seal spec, which is full contact for better durability. This ensures long lasting bearings even in wet conditions. For race-day bearings, we offer ceramic bearings that uses no-contact seals. This really provides low friction, while durability is ensured by the higher hardness of the ceramic balls.