Vortex 491ZR-37 Steel Rear Sprocket Pitch Sprockets - 37-Tooth 520

The Vortex 491ZR-37 is a 37-tooth steel rear sprocket designed for high-performance motorcycle applications using a 520 pitch chain. Built by Vortex Racing — a U.S.-based manufacturer trusted by professional race teams worldwide — this sprocket delivers the precision and durability demanded by serious street and track riders.

Key Features:

• 37-tooth rear sprocket for precise final drive gearing
• 520 pitch chain compatibility
• High-carbon steel construction for maximum strength and wear resistance
• Induction hardened teeth to reduce surface wear and extend service life
• Special Vortex nickel/zinc plating to resist corrosion
• Unique Vortex tooth profile — patented design for increased sprocket longevity
• Manufactured to precise tolerances to ensure concentricity and smooth chain engagement
• 100% CNC manufactured in the USA

Changing your rear sprocket tooth count is one of the most effective ways to tune your motorcycle's final gearing. A lower tooth count like 37T provides a taller gear ratio, improving top-end speed and reducing engine RPM at highway speeds. The Vortex 491ZR-37 is engineered to OEM-level fitment standards while offering the durability upgrades that racers and performance riders demand.