Acros AZ66 Block Lock Headset LowerSpecifically designed for the demands of modern mountain bike (MTB) and electric mountain bike (E-MTB) riding, this headset lower is developed for dependable performance as you hit the trails. It features a robust aluminium build for toughness and durability as you dominate your way around the mountain. Acros has also put this model through its CNC-machining process to shave off any unnecessary excess material, while still preserving maximum strength. As a result, it ensures an excellent strength to weight ratio for reliable, consistent performance, without any weight penalty.Headset Lower with Block Lock TechnologyThe main highlight of this high-quality component is its Block Lock system, which solves the issue of your handlebars swinging around and your shifter or dropper remote hitting your frame’s top tube. This versatile headset lower limits handlebar rotation using a special tab that’s CNC-machined into its cup, which then slides into a groove that’s machined in the top cap (top cap sold separately). When it comes to the end of the groove it stops, preventing any damage happening to your bike frame from low rise handlebars or shifters. The steering angle is limited to 164 degrees, which means if you set the mechanism centrally, it stops 13 degrees on either side of the top tube. One final highlight is it comes complete with double-sealed angular contact bearings for smooth rotative performance in all-weather conditions.Features: Cup Material: CNC-machined Aluminium Use: Mountain Bike (MTB), Electric Mountain Bike (E-MTB) Cup Skirt: 66mm Cup Skirt Length: 10mm Bearings: Double sealed angular contact bearings Fork Steerer: Multiple options available to select Included: Headset lower only Weight: 106gManufacturer’s Part Numbers: 5102620S120 Black 1.1/8" 5102625S120 Black 1.5"Buy Acros Components from Chain Reaction Cycles, the World’s Largest Online Bike Store.