Drivetrain› Manual Transmissions and Components

Doppler

Primary Gear Set

$97.01

SKU: 263894

Out of Stock
In Stock
Ships by Oct 11
Free Shipping over $200
$100 Minimum Order
Non-Returnable Item
INSTALL DIFFICULTY
DIY PRO SHOP

Moderate — 2–4 hours

Overview

The Doppler primary transmission is a 15/50 ratio gear set for Minarelli engines. Taller gears reduce the overall gear ratio, resulting in improved acceleration and increased top-end speed. It features a press-fitting mount and is compatible with various Yamaha, KTM, Benelli, Aprilia, MBK, Betamotor, Italjet, Keeway, and Malaguti models.
Show original supplier description
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.

Product descriptions are provided by our supplier partners and may not always be perfectly accurate. Not sure this fits? or call (760) 282-4645 and we’ll verify before you order.

Fitment

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Specifications

BrandDoppler
Part Number263894
CategoryDrivetrain
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Returns & Fitment

Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.

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Shipping

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