Vortex 190ZK-39 520 Aluminum Rear Sprocket 39T Black Anodized

The Vortex 190ZK-39 is a high-performance 39-tooth aluminum rear sprocket designed for 520-pitch chain applications. Built for riders who demand precision-engineered drivetrain components, this sprocket delivers a noticeable reduction in rotating mass compared to OEM steel units, translating to improved throttle response and sharper acceleration.

Key Features:

• 39 Teeth — Optimized tooth count for performance gearing applications
• 520 Chain Pitch — Compatible with 520-series chains (stock or conversion setups)
• Lightweight Aluminum Construction — Specially formulated alloy per Vortex specifications for maximum strength-to-weight ratio
• Black Anodized Finish — Durable anodized coating with contrast machined accents provides corrosion resistance and a clean race-inspired look
• 100% CNC Manufactured in the USA — Machined to tight tolerances for a perfectly concentric, smooth-running sprocket
• Optimized Tooth Profile — Vortex's proprietary tooth geometry reduces chain wear and extends drivetrain life
• Reduced Rotating Mass — Lighter than stock steel sprockets for improved acceleration and handling response

The Vortex 190ZK-39 rear sprocket is an ideal upgrade for street and track riders looking to fine-tune their gear ratios or replace worn OEM components with a premium aftermarket alternative. As with any sprocket replacement, it is recommended to replace the front sprocket and chain simultaneously for optimal wear and performance.