Chains & Sprockets for Metric Motorcycles. The Metric Chains & Sprockets collection at TC Bros is designed for riders and builders who demand durability and performance for their custom metric motorcycles. This category includes heavy-duty drive chains, sprockets, and conversion kits engineered for reliability and precision fitment. Perfect for iconic models like Yamaha XS650, Honda CB750, and other metric choppers or bobbers, these components deliver smooth power transfer and the rugged dependability needed for any road or build. With TC Bros’ reputation for quality and innovation, these products are built to withstand the demands of custom motorcycle enthusiasts who value performance and attitude.