Vortex 491ZK-42 Black 42-Tooth Aluminum Rear Sprocket

The Vortex 491ZK-42 is a 42-tooth aluminum rear sprocket finished in Vortex's black hardcoat anodizing — a PTFE-based coating that bonds directly to the aluminum surface for enhanced durability and reduced friction compared to standard anodizing.

Engineered and manufactured in the USA, this sprocket is 100% CNC machined from a specially formulated aluminum alloy to Vortex's exacting tolerances. The result is a lightweight component that reduces rotating mass in the drivetrain, contributing to improved acceleration, deceleration, and throttle response.

Key Features:

• 42-tooth rear sprocket — direct replacement or performance upgrade
• Black hardcoat (PTFE) finish — bonds to aluminum for increased surface hardness and corrosion resistance
• Lightweight aluminum construction reduces rotating mass for improved performance
• 100% CNC manufactured in the U.S.A. to tight tolerances
• Specially formulated alloy per Vortex specifications
• Vortex patented tooth design engineered to increase sprocket longevity
• Compatible with Vortex 491-series sprocket carrier applications

Vortex Racing is a U.S.-based manufacturer with over 15 years of experience producing high-performance motorcycle drivetrain components trusted by professional race teams in Motocross, Supercross, Road Racing, and Flat Track competition.