page_title: Suzuki RE5
section_title: History
hierarchical_section_title: Suzuki RE5 / History
context_page_description: The Suzuki RE5 is a motorcycle with a liquid-cooled single-rotor Wankel engine, manufactured by Suzuki from 1974 to 1976. Apart from its unusual engine, the RE5 is mostly a conventional roadster, albeit with some peculiar styling details thanks to Italian industrial designer Giorgetto Giugiaro.
context_section_description: RE5 project chief Shigeyasu Kamiya stated that Suzuki had considered a rotary-powered motorcycle in the mid-1960s. Research and development continued till the end of that decade, leading to the signing of a technical licence with NSU in November 1970, Suzuki being the 20th firm to do so. As a pioneer of rotary development, Suzuki engineers designed and produced numerous special machines for the rotary production process. Of these, ten were particularly notable and included the machine to cut the trochoid block. Suzuki holds twenty patents in plating, as considerable research went into the composite electro-chemical materials (CEM) used to plate the rotor housing. Prototypes testing took two years. The bikes were launched in 1974. Suzuki enlisted astronaut Edgar Mitchell, to introduce and endorse the bike. A number of motorcycle publications were given a lavish week-long opportunity for test riding. This RE5's warranty was unusually comprehensive, with a full engine replacement for any engine problem within the first 12 months or 12,000 miles (19,000 km).
  Despite having only a single rotor, the RE5's engine was mechanically complex and its numerous subsystems made for a heavy motorcycle. Rotary engines produce a lot of heat, and the RE5 had  water- and oil-cooling, and double-skinned exhaust pipes.  Ignition was CDI, with two sets of ignition points actuated via vacuum and rpm sensors, to light a solitary NGK spark plug. Three oil reservoirs served the sump, gearbox and total loss tank. Separate oil pumps fed (respectively) the main bearings and the inlet tracts (to lubricate tip seals). The throttle controlled both the primary carburetor butterfly and a second valve in the inlet manifold of the secondary throat (the "port" valve), as well as governing oil supply to the combustion chamber. Five cables in total were moved by the throttle twist grip! The carburetor was similar to that in a rotary-powered car, and was far more complicated than for normal motorcycles.
  The RE5 options included: a full touring kit that included a large full fairing (with lockable "glove boxes") and windscreen, two saddlebags, a large rack and lockable top box.
  Suzuki commissioned Italian industrial designer Giorgetto Giugiaro for the RE5 styling. The "tin can" instrument cluster encompassed the usual lights and a low-fuel warning light, total loss oil tank light and digital gear indicator.  The tubular "can" motif was also used in the tail light, and spherical indicator lights finished off the "rotary" theme.
  There were two production models of the RE5, the 1975 M model  and the 1976 "A" model, which adopted more conventional styling.  Many "A" models were converted M models. The main changes for 1976 included a color changes, GT750-style instruments, blinkers, tail lights and headlight housing. The "B" secondary points for overrun were removed on the "A" model, the chain oiler was removed and a sealed drive chain fitted. By the end of the production run, a total of some 6,000 RE5 machines had been produced.
  Although the RE5 was less powerful than the contemporary Suzuki GT750, the engine had excellent torque, and was generally smooth,  but it exhibited "grinding vibration" at around 4,000 rpm. Average fuel consumption was 37 mpg‑imp (7.6 L/100 km; 31 mpg‑US), varying between 28.6 mpg‑imp (9.9 L/100 km; 23.8 mpg‑US) and 43.3 mpg‑imp (6.52 L/100 km; 36.1 mpg‑US).
  The complex B-point system (explained below) gave smooth running on overrun and some engine braking. Suzuki stopped fitting the B points to the 1976 "A" model, and allegedly had dealers disconnect the system on remaining "M" models. The bikes sometimes exhibited a dead spot or hesitation during acceleration as the carburetor transitioned from primary to secondary throat. This was due to poor synchronization between the positions of the primary, port and the secondary carburetor throat valves. Some evidence links this to jetting, giving an excessively lean primary mixture.
caption: The "tin can" instrument cluster
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