Malossi's full circle is the ultimate crank for your dio. This model is a direct replacement for your AF16/af18 motor. These motors are commonly found in the united states sold bikes. The stuffer crank raises the compression in the crankcase, to promote better fuel/air mixture, with more force behind the fuel and air headed up to the combustion area. The malossi crank has no problem spinning to 14,000rpm. A more balanced crank, means more power, quicker revving, and a long lasting bottom end. Pair this with a malossi/polini bbk, and supporting mods, and I'd be shocked to see less than 65mph. The crank is the heart of your bike, don't cheap out here.
CHOOSE from af18 small spline, or af16 large spline