Today’s guest post is by Richard Fowler of Motorsport Retro.
This amazing piece of machinery was the last of the purebred 50cc Suzuki racebikes built in 1967. And it’s a technological as well as aesthetic masterpiece: the engine was tuned to an extraordinary 350hp per liter. The RK67 motor was a two-stroke, water-cooled parallel twin, and the Japanese factory managed to squeeze a remarkable 17.5hp out of it, with a redline of 17,300rpm. To keep the bike in its extremely narrow power band, Suzuki fitted the bike with a 14-speed gearbox. The RK67 also sported an aluminum frame, and tipped the scales at a skinny 58kg (128lbs): in the hands of Suzuki’s three factory riders, top speed was a healthy 176kph (109mph).
The 50cc class was first run in 1962, with Suzuki immediately setting the pace. But strong competition from Honda during the mid 60s forced Suzuki to develop micro-masterpieces like the RK67. In 1967, German rider Hans-Georg Anscheidt won the 50cc World Championship aboard the RK67, and with teammates Yoshimi Katayama and Stuart Graham, helped Suzuki lift the manufacturer’s crown too. Then the FIM announced in 1967 that it planned to limit future 50cc racing engines to a single cylinder and six transmission speeds. So Suzuki stopped the development of its next model, the 3-cylinder RP68, and withdrew from the World Championship at the end of 1967. However, Anscheidt ran the RK67 in the 50cc class in 1968, as a privateer—and once again won the Championship. A fitting swansong to one of the most remarkable racing motorcycles of all time.
[Thanks to Richard Fowler. Head over to Motorsport Retro for more vintage motorsports goodness of the two- and four-wheeled kind.]