CVT (Continuously Variable Transmission)

A CVT (continuously variable transmission), often just called the variator, is the stepless transmission used on almost every scooter and most ATVs and UTVs. There are no gears: the ratio changes smoothly with engine speed and load.

The front pulley (the variator) holds weighted rollers. As revs rise, centrifugal force throws the rollers outwards and squeezes the pulley halves together, so the belt climbs to a larger diameter. The rear pulley opens against the torque spring, and a centrifugal clutch finally drives the rear wheel.

The main tuning tool is roller weight: lighter rollers keep the revs higher for better acceleration, heavier ones lower the revs and can raise top speed. The belt and rollers wear out – a worn belt slips and the bike feels sluggish. Try different set-ups in our CVT simulator.