In the early 1970s, Suzuki was deadlocked in competition with Honda and Yamaha, Japan's other two big motorcycle manufacturers. In an expensive bid to stand apart, Suzuki began a three-year process to develop the Wankel rotary engine for a new motorcycle, tapping famous Italian designer Giorgetto Giugiaro for its forward-thinking design. Touted as the future of motorcycling, the RE5 debuted at the Tokyo Show in 1973, and went into production in 1974, making it the only mass produced rotary engine motorcycle to date.

The RE5's 497cc powerplant yielded 62 hp and delivered 54.9 ft.pounds of torque at 3,500 rpm. With no camshafts, intakes or exhaust valves, the engine itself was fairly simple, but its motorcycle application demanded some complex engineering. Since the engine produced so much heat, it needed a unique but cumbersome radiator for liquid cooling, and an air-cooled exhaust system to prevent burning legs. In order to properly lubricate the Wankel's seals, Suzuki needed to develop technology never seen on a motorcycle before. Although the RE5 has a traditional wet-sump oil system, the seals needed a secondary oil system to feed its new Mikuni 18-32 HHD two-stage carburetor. Weighing in at over five pounds, this complex carburetor has no less than five intake tubes and various linkages to prevent exhaust gasses from mixing with incoming fuel, for cleaner combustion. Suzuki also introduced a new, dual point ignition system, to accommodate the Wankel's tendency to pop and buck while accelerating with the throttle off.

Along with a 59-inch wheelbase, the RE5's five-speed transmission delivered an incredibly smooth ride. But its hefty curb weight of 573 pounds along with the Wankel's hefty appetite for gas, resulted in mileage of about 35 mph during the panicky days of the gas crisis of the 1970s. With limited sales, Suzuki stopped producing the RE5 by 1976. So while these unique motorcycles are still priced rather reasonably for collectors, their uniqueness may make finding replacement parts a tricky and expensive challenge.