Vortex 840ZK-42 CAT5 Rear Aluminum Sprocket 42T 530 Pitch Black

The Vortex 840ZK-42 is a CAT5 rear aluminum sprocket featuring a 42-tooth, 530-pitch design engineered specifically for motorcycles equipped with aftermarket wheels. This sprocket is compatible with popular aftermarket wheel brands including BST, Rotobox, and Core Moto Apex-6 wheels and is not intended for use with most OEM wheels.

Key Features:

• Material: 7075-T6 aerospace-grade aluminum — anodized first, then CNC machined for a precision contrast-cut finish with black color and silver highlights
• Tooth Count: 42 teeth
• Chain Pitch: 530
• Bolt Pattern: 5-bolt aftermarket pattern — M10 studs, 100mm bolt circle diameter (PCD), 76mm hub diameter
• Manufacturing: 100% CNC machined in the USA to Vortex's proprietary specifications
• Tooth Design: Patented saber-tooth groove profile for increased sprocket longevity
• Finish: Black anodized with contrasting silver machined accents
• Corrosion Resistance: Silver anodizing process helps protect against corrosion

The 840ZK series uses a 5-bolt aftermarket bolt pattern designed for high-performance wheels from BST, Rotobox, and Core Moto Apex-6 — it will not fit most standard OEM wheels. Vortex's CAT5 sprockets are proven in professional racing, including AMA Superbike and Pro Street Drag Racing competition, making them an ideal upgrade for track and performance street riders looking to reduce rotating mass and improve power transfer.