Rear Sprocket 50T 5.25 BC 520 Chain

The Rear Sprocket 50T 5.25 BC 520 Chain is a precision-engineered drivetrain component designed for micro sprint racing applications where reliability and consistency are non-negotiable. Built to handle the extreme torque and RPM demands of competitive sprint machinery, this 50-tooth rear sprocket serves as the final drive reduction point in your power delivery system. Whether you're tuning for acceleration on tight circuits or maximizing top-end speed on longer tracks, sprocket selection directly impacts throttle response, engine load, and overall lap performance.

Manufactured from lightweight aluminum, this rear sprocket features a 50-tooth profile optimized for 520 roller chain engagement, paired with a 5.25-inch bolt circle diameter for secure OEM-pattern mounting. The natural aluminum finish resists corrosion while maintaining a low unsprung weight—critical for minimizing rotational inertia and reducing gyroscopic load on suspension geometry. The 520 chain compatibility ensures proper tooth mesh geometry and load distribution across all engagement surfaces, reducing chain whip and extending drivetrain component lifespan even under continuous high-RPM operation.

Competitive micro sprint teams and weekend racers alike depend on this sprocket for consistent performance from dyno session through final heats. Installation requires standard metric tools and verification that your existing 520 chain and countershaft sprocket maintain proper tension and alignment. This 50-tooth configuration delivers balanced mid-range acceleration suitable for mixed-surface oval tracks; teams often stock multiple tooth counts (48T, 50T, 52T) to adapt to track surface, weather conditions, and race strategy. Weighing just 1.02 lbs, the minimal mass change when swapping sprockets preserves chassis tuning while allowing rapid gear ratio adjustments between qualifying and feature racing.