Vortex 491AZB-51 520-Pitch Aluminum Rear Sprocket 51-Tooth Black

The Vortex 491AZB-51 is a lightweight aluminum rear sprocket featuring a 520 chain pitch and 51 teeth with a black anodized finish. Designed for performance street and racing applications, this sprocket is 100% CNC machined in the USA from a specially formulated aluminum alloy to precise tolerances, ensuring optimal concentricity, consistent power transfer, and reduced rotating mass compared to a standard OEM steel sprocket.

Key Features:

• 520 Chain Pitch — compatible with 520-pitch chains for performance and conversion applications
• 51-Tooth rear sprocket for fine-tuning gear ratio and acceleration characteristics
• Aluminum construction — significantly lighter than OEM steel, reducing rotating mass for improved throttle response
• Black anodized finish — durable hardcoat treatment bonds to the aluminum surface for increased wear resistance and easy cleaning
• 100% CNC machined in the USA to tight tolerances for concentricity and durability
• Vortex patented tooth design increases sprocket longevity and chain engagement
• Lightening holes further reduce overall weight without sacrificing structural integrity

Vortex Racing rear sprockets are a trusted choice among road racers, track day riders, and performance street enthusiasts. The 491AZB-51 is part of Vortex's extensive rear sprocket lineup, available in a wide range of tooth counts to suit different gearing needs.