The scooter had rigid rear suspension and small wheels that allowed a compact design and plenty of room for the rider's legs. The Vespa's enclosed, horizontally mounted 98 cc two-stroke engine acted directly on the rear drive wheel through a three-speed transmission. The twistgrip-controlled gear change involved a system of rods. The early engine had no forced-air cooling, but fan blades were soon attached to the magneto-flywheel (which houses the points and generates electricity for accessories and for the engine's spark) to push air over the cylinder's cooling fins. The modern Vespa engine is still cooled this way.