High-Strength Aluminum Alloy Frame: Features a durable aluminum alloy frame that enhances strength and rigidity. It provides reliable support and stability for your bicycle, ensuring optimal performance and longevity Precision Ceramic Bearings: Equipped with high-quality ceramic bearings, delivers smooth and efficient pedaling. The ceramic bearings reduce friction and improve power transfer, making your ride more efficient and enjoyable Sealed Bearing Design: The sealed bearings offer superior protection against dirt, moisture, and contaminants, extending the lifespan and maintaining smooth operation even in harsh conditions Versatile Fit: Designed to fit bike frames with a bottom bracket shell width of 68-73mm, compatible with a wide range of bicycles, including road bikes and mountain bikes Lightweight Construction: Weighing approximately 110g, this bottom bracket provides a lightweight solution without compromising on strength or durability Specifications: Model: RN1985 Material: Aluminum alloy Inner diameter: Φ?24mm , reducer ring diameter: Φ?22mm Weight: about 110g Compatible Frame Width: 68-73mm