HTRoll - 28x19.9 gr. 26 CALIBRATED ROLLERS AD HIGH STRENGTH for original and Multivar variators. HTRolls are made of CPT with a specific formula and bear su one side the relative weight. The HTRolls represent a technical replacement to theoriginale and are a complete series of calibration elements able to vary the transmission ratio of your scooter by perfectly adjusting its speed and recovery. Operation As a result of rotation, the weight of the si transforms into centrifugal force: the higher the weight of the roller, the greater the centrifugal force and the less time it changes and vice versa. Calibration of the variator To le engine performance, adopt rollers that keep the engine in the maximum power rotation speed during use. By lightening the weight of the rollers the engine increases the number of operating revolutions, vice versa increasing the weight of the rollers decreases the number of revolutions.