Primary Gear Set

The Doppler Primary Transmission 15/50 is a performance upgrade designed to enhance your Minarelli-powered scooter or moped. This gear set features a 15/50 ratio, which increases the overall gear ratio, leading to improved acceleration and a higher top-end speed. It's important to note that this transmission requires a sports or racing cylinder to provide enough power to effectively utilize the taller gearing, as stock engines may lack the necessary output. If a press is not available, pre-assembled gears are recommended. The transmission itself has the crucial function of reducing RPMs and ultimately driving the wheel axle, directly influencing the vehicle's top speed. By choosing a longer gear ratio like this 15/50 set, you can achieve a higher top speed, provided the engine has sufficient power and torque at lower RPMs. This primary gear set is compatible with a wide range of motorcycle and scooter brands, including Yamaha, KTM, Benelli, Aprilia, MBK, Betamotor, Italjet, Keeway, and Malaguti. Specific fitment should always be confirmed with the compatibility table or by consulting your vehicle's service manual.