Engine & Clutch Parts for Metric Motorcycles. The Metric Engine & Clutch collection at TC Bros is crafted for riders and builders who demand top-tier performance and reliability for their custom metric motorcycles. This category features a range of high-quality components, including clutch cables, engine mounts, gaskets, and performance upgrades, all engineered to meet the needs of models like Yamaha XS650, Honda CB750, and other metric classics. Designed for durability and precision fitment, these parts deliver the power and smooth operation essential for custom chopper or bobber builds. With TC Bros’ commitment to quality, these products ensure your engine and clutch system perform as boldly as your bike looks.