The 50
cc class was the ultra-lightweight class in
Grand Prix motorcycle racing
Grand Prix motorcycle racing is the premier class of motorcycle road racing events held on road circuits sanctioned by the Fédération Internationale de Motocyclisme (FIM). Independent motorcycle racing events have been held since the start ...
, and formed part of the
Fédération Internationale de Motocyclisme (FIM) World Championships from 1962 until 1983; when the class was replaced by
80 cc.
History and development of the class
The relative low cost and increasing availability of 50 cc motorcycles in the post-war period, spawned a number of club
road racing
Road racing is a form of motorsport racing held on a paved road surface. The races can be held either on a closed circuit or on a street circuit utilizing temporarily closed public roads. Originally, road races were held almost entirely on publ ...
events for this size of machine in the early 1950s. With the earliest events being held in Italy
and in the UK.
The potential of this class for providing entertaining but affordable racing was soon recognised with several national championships and in 1961 the FIM introduced The Coupe d' Europe, a series of international events for 50 cc machines, each with a minimum duration and run to established Grand Prix rules and regulations.
The series attracted a variety of entries, but the dominating force were the work's
Kreidler
Kreidler was a German manufacturer of bicycles, mopeds and motorcycles.
Kreidler was originally based in Kornwestheim, between Ludwigsburg and Stuttgart. It was founded in 1903 as "Kreidlers Metall- und Drahtwerke" (Kreidlers metal and wire f ...
team bikes. Based on a standard Kreidler Florett road bike, their single
cylinder
A cylinder (from ) has traditionally been a three-dimensional solid, one of the most basic of curvilinear geometric shapes. In elementary geometry, it is considered a prism with a circle as its base.
A cylinder may also be defined as an infin ...
Kreidler Renn-Florett's featured lightweight frames, a special
cylinder head
In an internal combustion engine, the cylinder head (often abbreviated to simply "head") sits above the cylinders and forms the roof of the combustion chamber.
In sidevalve engines, the head is a simple sheet of metal; whereas in more modern ov ...
and barrel, twin 16 mm Bing
carburettor
A carburetor (also spelled carburettor) is a device used by an internal combustion engine to control and mix air and fuel entering the engine. The primary method of adding fuel to the intake air is through the venturi tube in the main meterin ...
s feeding the engine through
rotary valve
A rotary valve (also called rotary-motion valve) is a type of valve in which the rotation of a passage or passages in a transverse plug regulates the flow of liquid or gas through the attached pipes. The common stopcock is the simplest form of ro ...
s and improved suspension and brakes. By the end of the season, with the addition of rudimentary streamlining and the increase of carburettor size to 17 mm, the four-speed
two-stroke
A two-stroke (or two-stroke cycle) engine is a type of internal combustion engine that completes a Thermodynamic power cycle, power cycle with two strokes (up and down movements) of the piston during one power cycle, this power cycle being comple ...
bikes could top over 85 mph.
The 1961 Coupe d’Europe
World Championship Status
:''See
1962 Season,
1963 Season,
1964 Season,
1965 Season,
1966 Season,
1967 Season''
In
1962, the FIM followed up the success of the Coupe d’ Europe by giving the 50 cc class
World Championship
A world championship is generally an international competition open to elite competitors from around the world, representing their nations, and winning such an event will be considered the highest or near highest achievement in the sport, game, ...
status. As well as the works entries of existing European manufacturers like Kreidler and Tomos, this development also attracted entries from Japanese manufacturers with both
Honda
is a Japanese public multinational conglomerate manufacturer of automobiles, motorcycles, and power equipment, headquartered in Minato, Tokyo, Japan.
Honda has been the world's largest motorcycle manufacturer since 1959, reaching a product ...
and
Suzuki
is a Japan, Japanese multinational corporation headquartered in Minami-ku, Hamamatsu, Japan. Suzuki manufactures automobiles, motorcycles, All-terrain vehicle, all-terrain vehicles (ATVs), outboard motor, outboard marine engines, wheelchairs ...
entering full work's teams. The Spanish
Derbi
Derbi is a manufacturer of motorcycles, scooters, mopeds and recreational all-terrain vehicles produced by Nacional Motor S.A.U., a Spanish subsidiary of Piaggio & Co. SpA.
History
Derbi's origins began with a little bicycle workshop in the v ...
factory also entered a single work's bike for the
Spanish Grand Prix
The Spanish Grand Prix ( es, Gran Premio de España, ca, Gran Premi d'Espanya) is a Formula One motor racing event currently held at the Circuit de Barcelona-Catalunya. The race is one of the oldest in the world still contested, celebrating it ...
.
The Kreidlers were now fitted with three speed
overdrive
Overdrive may refer to:
Organizations
* OverDrive, Inc., a digital distributor of entertainment media
** OverDrive Media Console, a media player developed by OverDrive, Inc.
* Overdrive PC, a subsidiary of Velocity Micro
Technology
* Overdrive ...
s controlled from the
twistgrip
A twistgrip is a handle that can be twisted to operate a control. It is commonly found as a motorcycle's right handlebar grip to control the throttle, but is sometimes found elsewhere, such as on a bicycle as a gearshift, and in helicopters.
His ...
, which coupled to the standard four-speed
gearbox
Propulsion transmission is the mode of transmitting and controlling propulsion power of a machine. The term ''transmission'' properly refers to the whole drivetrain, including clutch, gearbox, prop shaft (for rear-wheel drive vehicles), differe ...
gave twelve gears to help keep the engines at maximum power. Engine development also increased power to at 11,000
rpm
Revolutions per minute (abbreviated rpm, RPM, rev/min, r/min, or with the notation min−1) is a unit of rotational speed or rotational frequency for rotating machines.
Standards
ISO 80000-3:2019 defines a unit of rotation as the dimensionl ...
. The Kreidlers development would be hampered however by the factory's insistence that the race bikes remained fundamentally based upon their standard road machines.
Suzuki and Honda knew no such limitations.
Honda's commitment to
four-stroke
A four-stroke (also four-cycle) engine is an internal combustion (IC) engine in which the piston completes four separate strokes while turning the crankshaft. A stroke refers to the full travel of the piston along the cylinder, in either directio ...
engines dated back to 1951 with the launch of its Dream E-Type
prior to this all Honda's bikes were two-strokes. The change and long-term commitment to the more sophisticated four-stroke technology came either directly from founder Soichiro Honda
or indirectly due to pressure from managing director Takeo Fujisawa, who was said to be appalled by the noise and smoke that two-stroke engines produced and the additional hassle that Honda customers faced by having to mix oil with their fuel.
Honda began their first 50 cc GP season with the
RC110, announced at the Japanese Motor Show in 1961. Powered by a single cylinder, four-valve engine, and with gear driven double overhead cams, giving about at 14,000 rpm. It was introduced with a five-speed gearbox, but by the time of the opening GP in Spain, the bikes were upgraded to six gears. Even so, they were badly outperformed. Rider
Tommy Robb suggested that more gears might be the answer and was amazed to find a week later at the French GP that the gearbox had been expanded to eight speeds. This still wasn't enough to compensate for the machine's relative lack of power and three weeks later at the
Isle of Man TT
The Isle of Man TT or Tourist Trophy races are an annual motorcycle racing event run on the Isle of Man in May/June of most years since its inaugural race in 1907. The event is often called one of the most dangerous racing events in the world ...
, nine gears were fitted and the rev limit increased to 17,000 rpm with output now up to around 10 hp. In that season, the machine's designation was changed to
RC111, but Honda's records are unclear as to what precise change in the development this signified or when it was used.
[Oxley, Matt (2001): ''The Challenge & Dream of Honda 500 Grand Prix Motor Cycle Wins''. Hazleton Publishing Ltd. p.146]
In contrast, the Suzuki team were committed to two-stroke technology and their single cylinder RM62 machine featured rotary valve induction and an 8-speed transmission and produced about at 12,000 rpm.
Ernst Degner
Ernst Degner (born Ernst Eugen Wotzlawek on 22 September 1931 in Gleiwitz, Upper Silesia, Germany - died 10 September 1983 in Arona, Tenerife, Spain) was a professional Grand Prix motorcycle road racer from Eastern Germany. Degner was noted f ...
who had defected from the East German
MZ team to Suzuki the previous year, brought with him the secrets of MZ's two-stroke tuning success which undoubtedly helped him and the Suzuki team to secure the inaugural 50 cc World Championship.
The Japanese withdraw
After the withdrawal of Japanese firms from the 50 cc category at the end of
1968
The year was highlighted by protests and other unrests that occurred worldwide.
Events January–February
* January 5 – "Prague Spring": Alexander Dubček is chosen as leader of the Communist Party of Czechoslovakia.
* Januar ...
, cost-saving technological restrictions were introduced, the Spanish rider
Angel Nieto
In various theistic religious traditions an angel is a supernatural spiritual being who serves God.
Abrahamic religions often depict angels as benevolent celestial intermediaries between God (or Heaven) and humanity. Other roles include ...
came to the fore, and between
1969 and
1976
Events January
* January 3 – The International Covenant on Economic, Social and Cultural Rights enters into force.
* January 5 – The Pol Pot regime proclaims a new constitution for Democratic Kampuchea.
* January 11 – The 1976 Phila ...
, won the championship six times. His season long battle for the
1972
Within the context of Coordinated Universal Time (UTC) it was the longest year ever, as two leap seconds were added during this 366-day year, an event which has not since been repeated. (If its start and end are defined using Solar time, me ...
championship with Dutchman
Jan de Vries, being perhaps the closest fought championship in any form of
motor racing
Motorsport, motorsports or motor sport is a global term used to encompass the group of competitive sporting events which primarily involve the use of motorized vehicles. The terminology can also be used to describe forms of competition of two ...
. By the end of the season both riders were tied with equal points, an equal number of wins and an equal number of second-place finishes and the championship winner was determined by adding together and comparing the times for the six races in which the pair had been placed. Nieto was calculated to have won the title by 21½ seconds from his rival.
50 cc GP World Champions
References
{{Grand Prix motorcycle racing
Grand Prix motorcycle racing