History of Sports Bikes
In the early days of motorcycling there were no true “sport” bikes. The first major racing events took place on board tracks designed for bicycle racing. These banked ovals were similar to the velodromes of today. Like their pedal-powered cousins, the motorcycles used on these ovals had the absolute minimum of equipment, forgoing brakes, gears, and often throttles to attain all-out performance.
The circle track craze died down during WWI to be replaced by hill climbing in the 1920s. It was at this time the first sport-centered bike came to market: the Brough Superior. This British bike company built approximately 3,000 motorcycles over a twenty year period with many of their models capable of speeds over 100mph. T.E. Lawrence, aka “Lawrence of Arabia,” owned seven of these bikes and died in an accident while riding one. Brough Superior closed after WWII.
After the war the Britain economy shifted from war production to general manufacturing, cranking out bikes and cars for import; most of this production went to America. Triumph and BSAs handled far better than their American rivals, letting them dominate racing. Meanwhile, the U.S. military was selling off surplus service bikes. Performance parts were nonexistent, so owners improved performance by cutting off anything they could to save weight. Thus the “chopper” was born.
Brough Superior’s place was taken by another British manufacturer, Vincent. Their Black Shadow was the fastest bike in the 40s and 50s with a top speed of 125mph. A racing version called the Black Lighting could reach 150mph. While sporty, it was still a general purpose machine designed with sidecar use in mind.
Harley Davidson created the “K” model in 1952 to compete with the British bikes. It combines a large-at-the-time 750cc engine with a lightweight frame with a top speed just over 100mph. In 1957 the bike got an overhead valve engine and was renamed the Sportster. Two years later Triumph released the Bonneville. This affordable twin cylinder bike could reach speeds of 110mph and became the template for all future British bikes. The two bikes had a rivalry lasting through the 60s.
In 1969 Honda radically changed the sport bike market with the CB750. The bike’s SOHC in-line 4-cylinder engine was far more advanced than any other mass produced bike and it was the first affordable bike with a front disc brake. Despite being cheaper than its British rivals, it provided superior performance with a top speed of 120 mph. The bike’s smooth engine and upright riding position also made it comfortable and practical, creating what was referred to as the “Universal Japanese Motorcycle.” Soon other Japanese brands had their own UJMs creating a class that dominated the market for most of the 1970s.
Meanwhile, Ducati began racing desmodronic V-twins, leading to the production of the 1973 750 SuperSport, the first in a long line of V-twin sport bikes. This basic design continues to be successful in racing while riders still debate the advantages and disadvantages of V-twin vs. in-line 4 engines.
The first modern sports bike came in 1984 with Kawasaki’s release of the GPZ900R “Ninja.” While the CB750′s engine had its output shaft in the center of the engine, the Ninja moved it to the side, creating a much narrower engine block. The frame used the engine as a stressed member to reduce weight and the bike was wrapped in an aerodynamic full fairing. This water-cooled DOHC motor produced 113hp. It was the first production bike with a top speed over 150mph.
Nearly all sport bikes from this era were designed for specific racing series, limiting their size and power. In 1999 Suzuki broke away from this group creating the Hayabusa. Its 1300cc engine was far larger than anything else on the market, allowing the bike to reach a record-setting 197mph. Soon after its release worries over safety forced the company to install a governor limiting the bike to 193mph. Its rival, the Kawasaki ZX-14, is also governed, although without this limitation it could exceed 200mph.