Rear Sprocket 42T 6.43 BC 520 Chain

The M AND W ALUMINUM PRODUCTS Rear Sprocket 42T 6.43 BC 520 Chain sprocket is engineered for riders and mechanics seeking precision drivetrain upgrades on 520 chain-equipped motorcycles and powersports vehicles. This 42-tooth rear sprocket serves as a mid-range gearing option that balances acceleration and top-end performance for street bikes and sport bikes. Whether you're fine-tuning your bike's power delivery or replacing a worn sprocket, this component is essential for maintaining optimal chain engagement.

Constructed from durable aluminum alloy, this sprocket delivers strength without excess rotating mass—a critical factor for acceleration response and fuel economy. The 6.43-inch bolt circle (BC) measurement ensures proper fitment to your motorcycle's hub, while the 520 chain pitch designation confirms compatibility with standard 520-specification drive chains used across countless platforms. M AND W Aluminum Products manufactures sprockets to exacting tolerances, with precisely machined teeth that reduce chain wear and vibration while promoting smooth power transfer from your engine to the rear wheel.

This 42-tooth sprocket benefits sportbike owners, street riders, and mechanics performing routine maintenance or custom drivetrain modifications. The lightweight 0.49-pound construction minimizes unsprung weight, improving handling and reducing stress on wheel bearings during aggressive riding. It's an essential upgrade for anyone looking to enhance their motorcycle's performance and efficiency.