Yamaha is a Japanese motorcycle manufacturer whose products are respected thanks to its exotic design and powerful performance. In the early 1970s, Yamaha ever make something other than the usual. At that time, secretly Yamaha was developing a motorcycle that uses Rotary/Wankel engine named Yamaha RZ201.
He is Hisao Koike, an engineer of Yamaha who had a major role in the creation of Yamaha RZ201, in cooperation with Gerber & Henn from NSU (as the patent holder Rotary/Wankel engine at the time). They developed this motorcycle plus to negotiate about the contract value of the using of Rotary engine.
|Yamaha RZ201 debuted at the Tokyo Motor Show 1972. (Picture from: http://adf.ly/1Y0CpV)|
At the time, the engine of Yamaha RZ201 developed entirely in Yanmar Diesel, a Japanese company which already has a license of NSU for the manufacture of Rotary/Wankel engine.
Finally, the motorcycle sketches and designs with project code of YZ587 approved on August 22, 1972, and officially introduced to the public for the first time at the event of Tokyo Motor Show 1972.
|Left side view of Yamaha RZ201. (Picture from: http://adf.ly/1Y0CpV)|
Yamaha RZ201 sudden presence at the exhibition site, became a very big surprise even for the employees of Yamaha itself. How not, because this motorcycle project is done in secret at Yanmar Diesel, and only known by few internal people of Yamaha.
By design, Yamaha RZ201 many uses identical parts with Yamaha TX750 and GL750. Starting from the use of tanks, frames, front dual-disc brake system, suspension, until other trinkets. And the using of the Rotary engine with 2 rotors, made the Yamaha RZ201 look very different when compared to other Yamaha motorcycle product available at that time.
|Rotary/Wankel engine used by Yamaha RZ201. (Picture from: http://adf.ly/1Y0CpV)|
With a rotor radius of 83 mm plus 56 mm, this machine has engine's cubication about 660 cc, and equipped with 2 cooling system as well, namely CCR (Charge Cooled Rotor) and OCR (Oil-Cooled Rotor). Yamaha claimed, the RZ201 can spew the maximum power up to 68 hp and maximum torque of 76.5 Nm. With these power figures, make the motorbike is able to beat the 4-stroke motorcycles in that time, that equipped with 750 cc engine.
Yamaha RZ201 is a true testament to the Yamaha seriousness to enter the motorcycle market which was then dominated by the brands from Europe and other Japanese competitors. In fact, Yamaha RZ201 is the first Japanese motorcycle that uses a Rotary engine. Well, armed with Dual-rotor Wankel engine, Yamaha RZ201 certainly has undoubted power to compete with 4-stroke motorcycles in that time.
But unfortunately, somehow Yamaha RZ201 not mass produced. So that its name of only fame as a brilliant motorcycle concept, and began to sink by the Suzuki RE5 successful mass produced by Suzuki in 1974. However, Yamaha RZ201 remain eligible to get a special tagline, as 'One of Yamaha's hidden treasures'. *** [EKA | FROM VARIOUS SOURCES |EA'S BLOG]
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