## Polini Secondary Gear 16/47 teeth The **Polini Secondary Gear 16/47 teeth** is an essential **transmission upgrade** designed by **Polini** for a wide range of Aprilia, Derbi, Gilera, Piaggio, and Vespa scooters manufactured from August 1998 onwards. This high-performance **secondary gear kit** significantly boosts your scooter's acceleration and top speed, transforming your riding experience with enhanced power delivery. ### Enhanced Performance and Durability This **Polini secondary gear set** is meticulously crafted to deliver superior power transfer and enduring reliability. With a precise **16/47 tooth configuration**, it optimizes your scooter's gearing, providing a noticeable improvement in overall performance. Manufactured from high-grade materials, these gears are built to withstand the rigorous demands of spirited riding, ensuring longevity and consistent power output. * Optimized **16/47 tooth ratio** for enhanced acceleration and higher top speed. * High-strength materials ensure long-lasting durability and reliability under stress. * Precision-machined components for flawless engagement and reduced wear. ### Precision Engineering for Optimal Power Transfer The **Polini 16/47 secondary gear** features a precise shaft diameter of **17.7mm**, ensuring a perfect fit and seamless integration into compatible engines. This advanced engineering minimizes friction and maximizes efficiency, translating into smoother power delivery and a more responsive throttle. Experience the difference a high-quality **Polini gear upgrade** makes to your scooter's responsiveness and dynamic capabilities. * Shaft diameter of **17.7mm** for precise, secure installation. * Designed to reduce power loss through optimized gear mesh and minimal friction. * Engineered for improved throttle responsiveness across the entire RPM range. ### Technical Specifications * Gear Ratio: 16/47 teeth * Shaft Diameter: 17.7mm * Application: Secondary transmission upgrade * Brand: Polini ### Compatibility * **Aprilia:** Mojito Custom 50, SR 50 (Funmaster, R, Racing, Sport, Street) (Piaggio engine) * **Derbi:** Atlantis 50 AC/LC (from 2002), GP 1 Open/Race/Revolution 50 * **Gilera:** Runner 50 2T (1999-2005), Stalker 50, Storm 50, Typhoon 50 * **Piaggio:** Fly 50 (up to 2011), Free 50, Liberty 50, NRG 50 (all mc2/mc3/Power variants), Typhoon 50, Zip 50 (all variants) * **Vespa:** ET2 50 (from 1997), LX 50, LXV 50, S 50 For a complete list of compatible vehicles, see the 'Fitment' section.