For those not familiar with it, Aprilia's Atlantic 500 was powered by Piaggio's X9 500cc single cylinder four stroke engine. For a single, it was impressively powerful, with about 40bhp at the crank and both of the Italian incarnations were as fast as the first version of Yamaha's twin cylinder Tmax500, just about capable of 100mph. On the downside, unlike the Tmax, the motor was a swinging unit, in traditional scooter style, so moved up and down with the rear wheel. Not ideal for best handling, especially with such a big, heavy unit. PNB