The exquisite HDB1 racer was designed by Massimo Tamburini, one of Bimota’s three founders. The ‘HD’ relates to the 488cc twin motor: in 1976, Harley-Davidson/Aermacchi engines provided power for three separate racing Bimotas. Only one of these HDB1 frames was built though, and Bimota’s association with HD was short-lived. Subsequent racers from the Rimini factory used Yamaha and Suzuki engines. Those beautiful wheels, by the way, are magnesium.