Triumph Ricardo
Encyclopedia
The Triumph Ricardo was a British
single-cylinder motorcycle
manufactured by the Triumph Engineering Co Ltd between 1921 and 1928. Named after engine designer Sir Harry Ricardo
it featured an innovative four valve head design and was capable of over 70 mph, set three world speed records and won a gold medal in the 1923 International Six Day Trial.
The rest of the cycle parts were based on Triumph's well proven Triumph Model H
side-valve. This had a poor reputation for handling, however, and was not really built for the more powerful four valve engine. On later models the oil system (which had relied on a manual hand pump) was replaced with an external oil pump. The 'Riccy' continued in production as a sports model until 1928.
, with only one completed the race but a 'Model R' Fast Roadster model was entered in the 1922 Senior TT
, ridden by Ricardo's assistant and fellow engine designer Frank Halford
, who came 13th. Halford on a tuned Triumph Ricardo fitted with a bronze alloy cylinder head of his own design also recorded a lap of the race track at Brooklands
at 68 mph, broke the Brooklands hour record at 76.74 mph the flying mile at 87.8 mph. Much of the credit went to the new racing fuel which was eventually banned.
In 1923 a 'Model R' Fast Roadster model won a gold medal in the ISDT.
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
single-cylinder motorcycle
Motorcycle
A motorcycle is a single-track, two-wheeled motor vehicle. Motorcycles vary considerably depending on the task for which they are designed, such as long distance travel, navigating congested urban traffic, cruising, sport and racing, or off-road conditions.Motorcycles are one of the most...
manufactured by the Triumph Engineering Co Ltd between 1921 and 1928. Named after engine designer Sir Harry Ricardo
Harry Ricardo
Sir Harry Ricardo was one of the foremost engine designers and researchers in the early years of the development of the internal combustion engine....
it featured an innovative four valve head design and was capable of over 70 mph, set three world speed records and won a gold medal in the 1923 International Six Day Trial.
Development
Developed around a 499cc single-cylinder four overhead valve four-stroke commissioned by Triumph from engine expert Ricardo, the Triumph Recardo was a replacement for the aging Triumph side-valves. Ricardo produced a number of prototypes aimed at reducing thermal stress on the inadequate valve materials available, while improving airflow through increased valve area. Harry Ricardo's final design had the four valves operated by the existing tappet mechanism and set a new standard for the power output possible from a 500cc single-cylinder engine, achieving over 20 bhp - the same as a 1500cc car engine of the time. Capable of 70 mph, the four-valve head allowed more efficient gas flow and the spark plug could be positioned in the middle for optimum combustion. Each pair of valves was parallel, at 90 degrees to each other, with the valve stems and springs exposed, as were the long pushrods which ran on the outside of the engine. A light alloy piston ran in a steel cylinder barrel and the cylinder head was made of cast iron.The rest of the cycle parts were based on Triumph's well proven Triumph Model H
Triumph Model H
The Triumph Model H is British motorcycle made by Triumph Engineering Co Ltd in Coventry, England.A total of 57,000 Triumph Model H motorcycles were made from 1915 until production ended in 1923.-Development:...
side-valve. This had a poor reputation for handling, however, and was not really built for the more powerful four valve engine. On later models the oil system (which had relied on a manual hand pump) was replaced with an external oil pump. The 'Riccy' continued in production as a sports model until 1928.
Racing success
As well as developing the four valve engine, Harry Ricardo was also very interested in formulating new racing fuels and the effects of fuel octane on engine performance. Triumph had a poor result when three Ricardo's competed in the 1921 Isle of Man TTIsle of Man TT
The International Isle of Man TT Race is a motorcycle racing event held on the Isle of Man and was for many years the most prestigious motorcycle race in the world...
, with only one completed the race but a 'Model R' Fast Roadster model was entered in the 1922 Senior TT
Isle of Man TT
The International Isle of Man TT Race is a motorcycle racing event held on the Isle of Man and was for many years the most prestigious motorcycle race in the world...
, ridden by Ricardo's assistant and fellow engine designer Frank Halford
Frank Halford
Major Frank Bernard Halford CBE FRAeS was an English aircraft engine designer.-Career:Educated at Felsted, In 1913 he left the University of Nottingham before graduating to learn to fly at Brooklands and Bristol Flying School and became a flight instructor using Bristol Boxkites.He served in the...
, who came 13th. Halford on a tuned Triumph Ricardo fitted with a bronze alloy cylinder head of his own design also recorded a lap of the race track at Brooklands
Brooklands
Brooklands was a motor racing circuit and aerodrome built near Weybridge in Surrey, England. It opened in 1907, and was the world's first purpose-built motorsport venue, as well as one of Britain's first airfields...
at 68 mph, broke the Brooklands hour record at 76.74 mph the flying mile at 87.8 mph. Much of the credit went to the new racing fuel which was eventually banned.
In 1923 a 'Model R' Fast Roadster model won a gold medal in the ISDT.