Description

VESPA SMALL FRAME GEAR CLUSTER AND GEARWHEEL KIT

Although it shares several elements with the motorcycle world, such as the gears, the Vespa can be considered the forefather of the scooter, yet it poses a number of challenges.
Lacking a conventional front and rear sprocket, the Vespa does not allow for the variation of its wheelbase. This makes it complicated to carry out any necessary modifications to support every performance increase – with the correct final drive ratio.
Initially, at Malossi, we sought a solution by creating a new gear kit that coupled with the stock components (art. 6716207), but we didn't stop until we found the perfect fit.

This is how our complete Vespa gear cluster and gearwheel kit was developed, featuring a different, more appropriate gear ratio set-up.
It is available in two versions, Sport and Racing, and it can be installed on various models, ranging between the Special 50 and the ET3 125.
What’s its distinguishing feature? Both sets of sprockets have the same number of teeth (Z) - calculated to provide an optimised transmission ratio - in both the Sport and Racing versions, while the module (that is the tooth profile) is different.

Furthermore, our designers have developed two distinct gear ratio set-ups for the second, third, and fourth gears, specifically calculated for this purpose:

• for engines focused more on torque, in the Sport version art. 6720145
• for engines tuned for the track, in the Racing version art. 6720146.

Technical specifications

• TAll gear clusters and gearwheel kits have been manufactured exclusively using materials that exceed our rigorous standards and are systematically verified through stringent testing.
• The final machining is performed on CNC (Computer Numerical Control) machines. Subsequently, the assembly is subjected to a thermo-chemical case hardening treatment at 900°C to achieve the required hardness and resistance.
• Finally, the size and quality of the finished gears are verified on Zeiss three-dimensional inspection machines.

The gearwheels are produced using CNC gear cutting machines and are precision ground on the contact surfaces. At these points, small oil pockets have been created to ensure the best lubrication of these critical areas. Lightening holes have been drilled in all gearwheels where possible, except in the contact section area between the gearwheel and the gear selector spider, thus preventing the creation of stress points.

4-speed gear ratios:

Products reserved exclusively for racing in specifically designed locations according to the provisions of the competent sporting authorities. We disclaim all liability for improper use