Primary Gears Polini Piaggio Zip \/ Vespa ET2 after 2000

Taller gears reduce the overall reduction factor of the gearbox. If the engine is powerful enough to pull the taller gears, this modification will also raise top speed. Only use with tuning kits! Original cylinders are normally not powerful enough to pull this sort of gearing. For all Piaggio engines built since ’99 with counter bearing in the gear cover.

Transmission ratio: 16\/37