Vortex 840AV4-42 Aluminum Rear Sprocket 42-Tooth 520-Pitch Silver

The Vortex 840AV4-42 is a lightweight aluminum rear sprocket featuring 42 teeth and a 520 chain pitch, designed for motorcycle road racing and high-performance street applications. Manufactured 100% in the USA, this sprocket is CNC-machined from a specially formulated aluminum alloy to Vortex's exacting specifications and finished with a silver anodize coating for corrosion resistance.

The 840 series is engineered for use with aftermarket wheels, featuring a 5-bolt mounting pattern with 10mm holes, a pitch circle diameter (PCD) of 100mm, and a sprocket inner diameter (ID) of 76mm. Vortex's patented tooth geometry promotes even chain wear and maximizes sprocket service life, while the reduced rotating mass compared to steel sprockets contributes to improved throttle response and drivetrain efficiency.

Key Features:

• 42-tooth, 520-pitch rear sprocket for precise gear ratio tuning
• Lightweight aluminum construction reduces rotating mass for improved acceleration and throttle response
• 100% CNC manufactured in the USA from a specially formulated aluminum alloy
• Silver anodized finish for corrosion resistance and lasting appearance
• Vortex patented tooth design for extended sprocket longevity and consistent chain engagement
• 5-bolt mounting pattern — 10mm holes, 100mm PCD, 76mm sprocket ID
• Compatible with 520-pitch drive chains

The Vortex 840AV4-42 is an ideal choice for riders looking to optimize gearing, reduce unsprung weight, or replace a worn OEM or aftermarket rear sprocket with a precision USA-made component.