The asymmetrical X-Tracker is a performance-engineered hub unit consisting of a double row angular contact ball bearing arrangement in which the outboard row has a larger diameter and contains more balls than the inboard row.
This unique design increases the bearing load carrying capacity and operational life, while significantly improving camber stiffness compared to traditional symmetrical hub units. Improving camber stiffness allows the brake rotor to tilt less during vehicle cornering. This reduces brake caliper piston knock back, allowing the driver to brake later, and reducing lap times on the track.
The small inner ring is retained with orbital forming which means the bearing will stay in preload under heavier loading, providing a longer service life.
The X-Tracker is currently used in a number of high-volume, high-performance luxury vehicles and will retrofit a number of racing and high performance car.