At DMG Motorsports, we present the Vortex F5 Rear Sprocket 840AK-40 — a 40-tooth, 520-pitch aluminum rear sprocket engineered for Yamaha applications that demand less rotating mass without sacrificing durability. Vortex sprockets are trusted throughout roadracing paddocks for their strength-to-weight ratio, precision manufacturing, and signature jet-black finish, making this F5 sprocket a smart upgrade for riders looking to shed unsprung weight, sharpen acceleration, and dial in gearing on their Yamaha.

Built from aircraft-grade 7075 aluminum and finished with Vortex's proprietary hard anodizing and PTFE topcoat, the 840AK-40 is designed to hold up to serious street and track use while keeping the drivetrain looking as good as it performs. The unique tooth profile helps extend the working life of both the sprocket and chain, and the reduced rotating weight compared to steel translates directly into quicker acceleration and deceleration.

Features:

• CNC machined from 7075 aluminum for outstanding strength combined with light weight
• Hard anodized with a jet black dye for a clean, aggressive appearance
• PTFE coated for added lubricity, wear resistance, and long-term durability
• Unique patented tooth design that increases sprocket and chain longevity
• 40-tooth, 520-pitch configuration for Yamaha applications
• Lightweight rotating mass helps improve acceleration and deceleration
• 100% CNC manufactured to tight tolerances for precise, concentric fitment
• Proven Vortex F5 design trusted by champions in road racing