Vortex 610ZK-39 520 Aluminum Rear Sprocket 39T Black

The Vortex 610ZK-39 is a high-performance, lightweight aluminum rear sprocket featuring a 39-tooth, 520-pitch configuration with a black anodized finish. Designed as a direct replacement for stock steel sprockets, this sprocket reduces rotating mass to deliver improved throttle response and faster acceleration.

Key Features:

• 520 Pitch — compatible with standard 520-series drive chains
• 39 Teeth — optimized tooth count for balanced acceleration and top-end performance
• Black Anodized Finish (ZK) — corrosion-resistant anodizing provides long-lasting protection and aggressive styling
• Premium 7075-T6 Aluminum Construction — specially formulated alloy per Vortex specifications delivers an ideal strength-to-weight ratio
• 100% CNC Manufactured in the USA — precision-machined to tight tolerances ensuring perfect concentricity and reduced chain wear
• Unique Saber Tooth / Mud Groove Design — Vortex patented tooth profile increases sprocket longevity and reduces drag and friction
• Reduced Rotating Mass — lighter than OEM steel sprockets, helping put more power to the ground

The Vortex 610ZK-39 is engineered for riders who demand race-proven quality without sacrificing durability. As with all Vortex sprockets, it is recommended to replace the front sprocket and drive chain simultaneously to prevent accelerated wear on new components.