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.

Features

• Optimized for 1-1/2" Forks: Designed for frames with a 55mm head tube, offering enhanced rigidity and consistent steering precision across terrains.
• SHIS Standard Compatibility: Built to ZS55/40 specification for seamless fitment with semi-integrated (Zero Stack) headsets on modern performance bikes.
• Precision-Built Construction: Machined to exact tolerances, ensuring low friction, reduced play and improved steering response even under heavy loads.
• Durable and Smooth Operation: High-quality materials ensure wear resistance, maintaining buttery-smooth steering through extended use.
• Sealed for Longevity: Fully sealed against moisture and debris to prevent corrosion and preserve performance in all weather conditions.

Specifications

• Product Number: HE-ZS55/40
• Type: Semi-integrated
• Position: Down
• SHIS: ZS55/40
• S.H.I.S Lower: ZS55/40
• Frame Diameter: 55 mm
• Fork Pivot Diameter: 1-1/2 inch (40 mm)