Vortex 491AZK-40 525-Pitch 40-Tooth Black Aluminum Rear Sprocket

The Vortex 491AZK-40 is a 40-tooth, 525-pitch black anodized aluminum rear sprocket designed for performance street and track riding. Precision CNC-machined from a specially formulated aluminum alloy to Vortex's exacting standards, this sprocket delivers the ideal combination of lightweight performance and long-term durability.

Compared to a stock steel sprocket, the aluminum construction significantly reduces rotating mass, contributing to sharper throttle response and improved acceleration. The black anodized finish provides corrosion resistance and a clean, aggressive look. Vortex's patented unique tooth geometry optimizes chain engagement and release, extending the service life of both the sprocket and chain.

Key Features:

• 525 chain pitch — must be paired with a matching 525-pitch chain and front sprocket
• 40 teeth — rear sprocket tooth count for precise gear ratio tuning
• Black anodized finish — corrosion-resistant and visually distinctive
• Lightweight aluminum construction — reduces rotating mass for improved acceleration and handling
• 100% CNC manufactured in the USA — machined to the tightest tolerances for concentricity and durability
• Vortex patented tooth design — increases sprocket longevity and optimizes chain hold and release
• Lightening holes engineered into the carrier further reduce unsprung weight

Vortex Racing has been manufacturing top-quality motorcycle racing components in the USA since 1995. Every sprocket is built to race-proven specifications and tested with feedback from professional race teams worldwide. The 491AZK-40 is the choice for riders who demand performance-grade hardware for both street and circuit use.