Blackbearing Zs5540 Lower Headset Bearing

The Blackbearing ZS55/40 Lower Headset Bearing is designed for riders who demand precision, stability and smooth steering performance. Crafted for semi-integrated headset systems, it ensures a secure interface between the frame and fork for confident handling on any terrain.

Optimized for 1-1/2″ Forks: With a 40mm fork steerer diameter and 55mm frame diameter, this bearing fits modern frames using 1-1/2″ lower headset configurations. The sizing ensures perfect alignment, improved rigidity and consistent steering control.

SHIS Standard ZS55/40 Compatibility: Engineered according to the SHIS ZS55/40 standard, it provides a direct fit for semi-integrated (Zero Stack) headsets. This makes it a reliable replacement for original bearings in high-performance road, gravel and MTB setups.

Precision-Built for Performance: Constructed from premium-grade materials, the ZS55/40 bearing ensures low friction and smooth rotation under varying loads. The precision machining enhances fit accuracy, reducing play and improving steering response.

Fully sealed against moisture and dirt, it resists corrosion and contamination, ensuring long-lasting durability. The Blackbearing ZS55/40 Lower Headset Bearing delivers a perfect combination of strength, protection and refined steering feel.