Vortex 840AZR-51 Azure Blue Aluminum Rear Sprocket 51T 530 Chain BST Wheels

The Vortex 840AZR-51 is a 51-tooth aluminum rear sprocket designed for motorcycles equipped with BST (BlackStone Tek) carbon fiber wheels, compatible with 530 pitch chains. Finished in a striking azure blue anodized coating, this sprocket delivers a perfect blend of race-proven performance and visual style.

Key Features:

• 51-tooth count for optimized gear ratio and drive performance
• 530 chain pitch compatibility — verify your bike's OEM chain pitch before ordering
• Manufactured from 7075 T6 billet aluminum for maximum strength with minimal weight
• 100% CNC machined in the USA to the tightest tolerances
• Azure blue anodized finish applied before machining, producing the iconic Vortex two-tone machined look
• Vortex patented tooth design reduces wear and increases sprocket longevity
• Specially designed mounting pattern for BST carbon fiber aftermarket wheels
• 5-hole mounting pattern with a 100mm Pitch Circle Diameter (PCD) and 76mm sprocket ID

Sprocket Dimensions:

• Bolt Pattern: 5 x 10mm holes
• PCD (Pitch Circle Diameter): 100mm
• Sprocket ID: 76mm

Vortex Racing has been manufacturing championship-level motorcycle components in the USA since 1995. Their aluminum sprockets are the preferred choice for road racing, motocross, flat track, and high-performance street applications where reducing rotational mass translates directly to improved throttle response and rear-wheel power. For best results, clean and tension the chain every 300–400 miles when running an aluminum sprocket.