Triumph Speed Twin
Encyclopedia
The Speed Twin 5T is a motorcycle
that was made by Triumph at their Coventry
factory. Edward Turner
, Triumph’s Chief Designer and Managing Director, launched the Triumph Speed Twin at the 1937 National Motorcycle Show. It was a 500 cc OHV vertical twin in a lightweight frame and the first truly successful British twin, setting the standard for many twins to follow. After World War II
the Speed Twin was responsible for the survival of Triumph - and every major British marque offered a 500 cc twin designed on similar lines to the Speed Twin.
red' with hand painted gold pinstripes to set off the chrome. Initially the one piece iron cylinder was secured with six studs which led to weakness, so these were replaced by eight studs.The two cylinders were fed by a single Amal
Type 6 carburettor and many features such as the transmission and clutch were straight from the Triumph single. Originally with girder forks, the sprung saddle was the only rear suspension as the Speed Twin had a rigid frame
- also from the single cylinder production line. On the night of 14 November 1940 the majority of the city-centre of Coventry
was destroyed by German bombs and the Triumph factory (which was working on an order of thousands of military specification 5T's) was completely wiped out, and all of Triumph's technical records, drawings and designs were destroyed.
was largely due to the Speed Twin, which was developed in 1946 with telescopic forks and optional (sprung hub) rear suspension. The headlamp and instrument area was tidied up in 1949 with the Turner-designed nacelle
, a feature retained until the end of the model line. In 1953, the Speed Twin caused controversy among traditional British riders as the generator and magneto were replaced with a Lucas alternator and battery/coil ignition system.
Further development led to the 1959 model 5TA with a unit engine and gearbox construction
and styling changes including the unpopular 'Bathtub' fairing which became more and more abbreviated as the model developed before disappearing altogether for the last year of production in 1966.
The unit 500 engine continued development in the parallel Tiger 100
range ending with the Tiger Daytona
models which ceased production in 1973.
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...
that was made by Triumph at their Coventry
Coventry
Coventry is a city and metropolitan borough in the county of West Midlands in England. Coventry is the 9th largest city in England and the 11th largest in the United Kingdom. It is also the second largest city in the English Midlands, after Birmingham, with a population of 300,848, although...
factory. Edward Turner
Edward Turner
Edward Turner was a British motorcycle designer. He was born in Camberwell in the London Borough of Southwark, on the day King Edward VII was proclaimed King....
, Triumph’s Chief Designer and Managing Director, launched the Triumph Speed Twin at the 1937 National Motorcycle Show. It was a 500 cc OHV vertical twin in a lightweight frame and the first truly successful British twin, setting the standard for many twins to follow. After World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
the Speed Twin was responsible for the survival of Triumph - and every major British marque offered a 500 cc twin designed on similar lines to the Speed Twin.
History
Edward Turner’s Triumph twin was a major turning point for the British motorcycle industry, as although a 500 cc parallel twin of medium capacity was not revolutionary, the 5T Speed Twin model was lighter than many contemporary singles with significantly more power and torque. Early models were only available in 'AmaranthAmaranth
Amaranthus, collectively known as amaranth, is a cosmopolitan genus of herbs. Approximately 60 species are recognized, with inflorescences and foliage ranging from purple and red to gold...
red' with hand painted gold pinstripes to set off the chrome. Initially the one piece iron cylinder was secured with six studs which led to weakness, so these were replaced by eight studs.The two cylinders were fed by a single Amal
Amal (motorcycle)
AMAL is a British carburettor trademark. AMAL were the suppliers of carburettors to the British motorcycle industry and their products were present on the products of the largest British motorcycle manufacturers such as BSA and AMC...
Type 6 carburettor and many features such as the transmission and clutch were straight from the Triumph single. Originally with girder forks, the sprung saddle was the only rear suspension as the Speed Twin had a rigid frame
Rigid frame
A rigid frame in structural engineering is the load-resisting skeleton constructed with straight or curved members interconnected by mostly rigid connections which resist movements induced at the joints of members. Its member can take bending moment,shear and axial loads....
- also from the single cylinder production line. On the night of 14 November 1940 the majority of the city-centre of Coventry
Coventry
Coventry is a city and metropolitan borough in the county of West Midlands in England. Coventry is the 9th largest city in England and the 11th largest in the United Kingdom. It is also the second largest city in the English Midlands, after Birmingham, with a population of 300,848, although...
was destroyed by German bombs and the Triumph factory (which was working on an order of thousands of military specification 5T's) was completely wiped out, and all of Triumph's technical records, drawings and designs were destroyed.
Development
After the war the recovery of Triumph at MeridenMeriden, West Midlands
-External links:*****...
was largely due to the Speed Twin, which was developed in 1946 with telescopic forks and optional (sprung hub) rear suspension. The headlamp and instrument area was tidied up in 1949 with the Turner-designed nacelle
Nacelle
The nacelle is a cover housing that holds engines, fuel, or equipment on an aircraft. In some cases—for instance in the typical "Farman" type "pusher" aircraft, or the World War II-era P-38 Lightning—an aircraft's cockpit may also be housed in a nacelle, which essentially fills the...
, a feature retained until the end of the model line. In 1953, the Speed Twin caused controversy among traditional British riders as the generator and magneto were replaced with a Lucas alternator and battery/coil ignition system.
Unit construction
Unit construction is a term used to describe the design of larger motorcycles where the engine and gearbox components share a single casing. The term is sometimes applied to the design of automobile engines and was often loosely applied to motorcycles with rather different internal layouts such as...
and styling changes including the unpopular 'Bathtub' fairing which became more and more abbreviated as the model developed before disappearing altogether for the last year of production in 1966.
The unit 500 engine continued development in the parallel Tiger 100
Triumph Tiger 100
The Triumph Tiger 100 was a British motorcycle first made by Triumph at their Coventry factory for 1939.With the runaway sales success of the Triumph Speed Twin, Edward Turner's mind turned to further developing the potential of his new parallel twin motor...
range ending with the Tiger Daytona
Triumph Tiger Daytona
The Triumph Tiger Daytona is a motorcycle made by Triumph from 1967 to 1974.-Development:The 'Daytona' name was derived from American rider Buddy Elmore's win at the 1966 Daytona 200 race held at the Daytona International Speedway in Daytona Beach, Florida...
models which ceased production in 1973.