At DMG Motorsports, we present the Vortex F5 Rear Sprocket, Aluminum 39T-520 Black Hardcoat for Yamaha (642AK-39 / 3-654AK39) — a race-bred drivetrain upgrade built to shed weight without sacrificing strength. Vortex has long been a favorite among racers and trackday riders, and the F5 Hardcoat series takes their proven aluminum sprocket design a step further with a tougher, longer-lasting finish that keeps your bike looking sharp while performing at its best. Whether you're chasing lap times or simply want a lighter, more responsive rear wheel, this sprocket delivers the reduced rotating mass that translates into quicker acceleration and crisper handling.

Features:

• CNC machined from 7075 aluminum for amazing strength and light weight
• Hard anodized with a jet black dye for a durable, race-ready look
• PTFE (Teflon-type) coated over the hardcoat for added lubricity, easier cleaning, and extended durability
• Unique tooth design engineered for smooth chain engagement and release
• Improved concentricity for a stronger, quieter, longer-lasting sprocket
• Lightweight aluminum construction reduces unsprung rotating mass versus OEM steel sprockets, aiding acceleration and handling
• 520 pitch, 39-tooth configuration designed to fit specified Yamaha applications
• Trusted by champions on the track and street