Gear set - manual or automatic, electric start, 1+1. Commonly referred to as 'transmission gear set' or 'gearbox gear set'. Most commonly (though not exclusively) applicable to 50cc, 70cc, 90cc and 110cc '1+1' configuration dirt bikes, ATVs, dune buggies and go karts as well as other powersports and mobility products. The 2 smaller gears on one shaft have 20 teeth and 12 teeth, the 2 larger gears on the shaft have 30 teeth and 27 teeth.