Aprilia's Sportgear system is a sophisticated spin-off of your basic Constant Variable Transmission that works by varying the contact points between two conical drive pulleys and a tough V-section belt. An impressive array of sensors, microprocessors and an electric motor ensures that shifts happen quickly and on cue, but the basic idea remains the same: Pulling the two cones that form the drive pulley drops the belt onto a smaller-diameter pulley. Bring them together and the belt rides up onto the larger-diameter surface. Decrease drive-pulley diameter while increasing diameter on the driven pulley spins the driven side faster, lowering the ratio in play. Want a taller gear? Reverse the process.