The most prestigious are the "Grand Prix" road races held in several European countires each year, and result in the award of the rider's trophy and manufacturer's trophy based upon the number of points the driver and equipment received during the season. The Grand Prix's are broken down according to the displacement of the motorcycle engine, and the 500cc class is regarded as the top ranked, most sought after racing title. Since 1979, four Japanese manufacturers hace been entering their 500cc class racing bikes in Grand Prix competition, along with the others, and the racing is becoming more exciting and competitive.
Suzuki's challenge to world motorcycle competiition started in 1960, and they were very successful with their 50cc and 125cc bikes; however, in 1967 they pulled out of competition at the Grand Prix level, but remained active and successful in world motocross competition. In 1974, Suzuki rejoined the Grand Prix circuit with an eye to winning the 500cc competition, but the next two years were not as successful as they would have liked; however, the Suzuki Motor Co. was not dismayed and continued developing and testing new ideas and concepts, knowing that all would shrtly come together with a big win. In 1976, they won both the manufacturer's trophy and the rider's trophy due to the excellent driving of Barry Sheene. Since then, Suzuki has been in the forefront of 500cc competition at the Grand Prix level winning both trophies again in 1977, and the manufacturer's trophy each year from 1976 to 1980. During these victory years, Suzuki has been continuously developing and improving their bikes. The RGB 500, which won the manufacturer's trophy in 1980 is powered by a 4 cylinder, 2 stroke, water-cooled engine of 495cc displacement. The layout of the engine is in the "Square 4" format, developed by Suzuki in the 1960's to produce more power, and the 1980 version produces more than 110 horsepower. The front two cylinders sit in a lower position than the rear two, so that the airflow through the radiator is not obstructed, and contributes to a lower center of gravity. This bike also has the "Anti Nose Dive" front forks, that limit shock strut movement during braking, plus a full floating rear suspension system, developed first for their motocross bikes. All of these innovations provide excellent stability and handling.