The Yamaha RD56 was a
two stroke
A two-stroke (or two-stroke cycle) engine is a type of internal combustion engine that completes a power cycle with two strokes (up and down movements) of the piston during one power cycle, this power cycle being completed in one revolution of t ...
250cc
Grand Prix
Grand Prix ( , meaning ''Grand Prize''; plural Grands Prix), is a name sometimes used for competitions or sport events, alluding to the winner receiving a prize, trophy or honour
Grand Prix or grand prix may refer to:
Arts and entertainment ...
racing motorcycle. It had two 56x50mm cylinders, disk valves and an
Oldham coupler
A coupling is a device used to connect two shafts together at their ends for the purpose of transmitting power. The primary purpose of couplings is to join two pieces of rotating equipment while permitting some degree of misalignment or end mov ...
joining the crank shafts. Power was 47 bhp at 11,000rpm. Although the engine was essentially the same as that of the
RD48, the frame was a new design based on the
Norton Featherbed. It featured a 7 speed gearbox.
It was ridden by
Yoshikazu Sunako
was a Japanese motorcycle racer and racing driver.
Sunako was a works rider for Yamaha during the late 1950s and early 1960s. After racing in Japanese events, Sunako made his Grand Prix motorcycle racing debut in the 1961 Belgian Grand Prix, wh ...
,
Fumio Ito
was a Japanese professional Grand Prix motorcycle racing, Grand Prix motorcycle road racing, road racer. Ito began his Grand Prix career in 1960 Grand Prix motorcycle racing season, 1960, although he was a Factory Yamaha rider as far back as 19 ...
,
Hiroshi Hasegawa and
Tony Godfrey for the
1963 Grand Prix season.
The engine was improved for the
1964 season generating a claimed 50 bhp at 11,000 rpm.
[p25 MacKellar] Phil Read
Phillip William Read, (1 January 1939 – 6 October 2022) was an English professional motorcycle racer. He competed in Grand Prix motorcycle racing from 1961 to 1976. Read is notable for being the first competitor to win world championships ...
joined the Yamaha team and narrowly beat Redman to become Grand Prix World Champion.
Hiroshi Hasegawa won the 1967
Macau Grand Prix
The Macau Grand Prix ( pt, Grande Prémio de Macau; ) is a motorsport road race for automobiles and motorcycles held annually in Macau. It is the only street circuit racing event in which both cars and motorcycles participate, and one of onl ...
.
References
Bibliography
{{motorcycle-stub
RD56
Grand Prix motorcycles