BSA Golden Flash
Encyclopedia
The BSA Golden Flash was a Birmingham Small Arms Company
(BSA) motorcycle
. The Golden Flash was also available in black and chrome, but it was the all-over gold paint scheme that gave it the name, and made it such a popular escape from post war austerity.
Its development after the 1937 launch of the ground breaking Triumph Speed Twin
, together with the need to pay off British war-debt, led to the two creating the post-war rise of the parallel twin
engine layout, which was to dominate British design throughout the 1950s and 60s.
had left school to serve an apprenticeship under designer Val Page
at Ariel
. In 1936, Hopwood moved to Triumph, where he worked under Edward Turner
to develop the ground breaking Triumph Speed Twin
. Post World War II, Hopwood accepted an offer in April 1947 from Norton, where he designed the Norton Dominator
engine.
The movement of Hopwood around the three manufacturers meant that all three were ahead of BSA in manufacturing a modern parallel-twin. The then largest and most financially stable manufacturer needed to compete, and although it had launched a pre-war designed parallel-twin in the form of the BSA A7
, it was possibly fateful that Hopwood fell out with Norton, and left the company 12 months after joining them.
Launched in October 1949, the A10 Golden Flash was a new post-war design, with most of the difference to the A7 being in the engine. Increased to 650 cc, it encompassed revised castings for the cylinder head and rocker box, and a cast-in carburettor manifold. The frame was available in rear rigid format, but the more common option was the then new plunger suspension, specifically designed for overseas export. BSA was a manufacturer who focused on machines for the working man, and so the design incorporated two practical use features: a hinged rear mudguard, designed to ease rear wheel removal; and a semi-unit engine and gearbox arrangement. The semi-unit power train enabled the primary chain to be adjusted via a slipper within the primary chain case.
Although never designed as a fast machine, the Golden Flash was none the less fast for its time and competitive with the Triumph Tiger 100
, achieving over 100 miles per hour (160.9 km/h) in tests in 1950, and covering a standing quarter mile in under 16 seconds. Its gold colour also made it a marketing and sales success, out selling the red Speed Twin and the later blue-grey Triumph 6T Thunderbird
, which was resultantly revised the following year into polychromatic blue.
However, BSA were concerned about a tendency for wear in the rear, plunger suspension, leading to uncertain handling. In 1954 it revised the model with a modern swinging arm, and the hinged mudguard was deleted. The semi-unit power train was also abandoned, making for a more involved procedure for adjustment of the primary chain, it offered benefits in the areas of the clutch and gearbox internals. The revisions also allowed for the launch of more sporting A10 Road Rocket.
In 1956, alloy brake drums were fitted as standard which both reduced unsprung weight and increased stopping power.
In 1957, the 40bhp 105 miles per hour (169 km/h) BSA Super Rocket
was launched for the 1958 season, with an Amal TT carburettor and high lift cam.
The final A10 development, and fastest in terms of power and performance, the 1962 BSA Rocket Gold Star
, which fitted a tuned A10 Super Rocket engine into the well proven BSA Gold Star
single frame. The result was a good handling fast bike that was a true classic. Current demand for the Rocket Gold Star, or "RGS", is such that non-RGS A10s are sometimes sold as originals, having been modified using suitable alternative parts.
With the launch of the new unit-construction (combined engine/gearbox) BSA A50 and BSA A65, the A7 and A10 were discontinued at the end of 1962 but the Rocket Gold Star continued into 1963 production.
Birmingham Small Arms Company
This article is not about Gamo subsidiary BSA Guns Limited of Armoury Road, Small Heath, Birmingham B11 2PP or BSA Company or its successors....
(BSA) 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...
. The Golden Flash was also available in black and chrome, but it was the all-over gold paint scheme that gave it the name, and made it such a popular escape from post war austerity.
Its development after the 1937 launch of the ground breaking Triumph Speed Twin
Triumph Speed Twin
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...
, together with the need to pay off British war-debt, led to the two creating the post-war rise of the parallel twin
Straight-two
A straight-two engine, is a two-cylinder piston engine that has its cylinders arranged side by side....
engine layout, which was to dominate British design throughout the 1950s and 60s.
Background
Bert HopwoodBert Hopwood
Herbert "Bert" Hopwood was a British motorcycle designer. He helped with some of the most influential designs for the British motorcycle industry and worked for Ariel, Norton, BSA and Triumph.-Motorcycle design career:...
had left school to serve an apprenticeship under designer Val Page
Val Page
Valentine Page was a British motorcycle designer born in 1892. Described as Britain's greatest motorcycle designer, he worked for most of the leading marques, including Ariel, Triumph, and BSA. He died in 1978.-J.A Prestwich:...
at Ariel
Ariel (vehicle)
Ariel was a bicycle, motorcycle and automobile marque manufacturer based in Bournbrook, Birmingham, England. Car production moved to Coventry in 1911. The company name was reused in 1999 for the formation of Ariel Ltd, a sports car producer.-History:...
. In 1936, Hopwood moved to Triumph, where he worked under 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....
to develop the ground breaking Triumph Speed Twin
Triumph Speed Twin
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...
. Post World War II, Hopwood accepted an offer in April 1947 from Norton, where he designed the Norton Dominator
Norton Dominator
The Dominator is a twin cylinder motorcycle developed by Norton to compete against the Triumph Speed Twin. The original Dominator was designed in 1947 and 1948 by Bert Hopwood, who had been on the Speed Twin design team at Triumph....
engine.
The movement of Hopwood around the three manufacturers meant that all three were ahead of BSA in manufacturing a modern parallel-twin. The then largest and most financially stable manufacturer needed to compete, and although it had launched a pre-war designed parallel-twin in the form of the BSA A7
BSA A7
The BSA A7 was a British motorcycle manufactured by Birmingham Small Arms Company at their factory in Armoury Road, Small Heath, Birmingham in 1946. There were actually two versions of the A7, the original 495cc version and an improved 497cc version launched in 1950...
, it was possibly fateful that Hopwood fell out with Norton, and left the company 12 months after joining them.
Development
In May 1948, Hopwood joined BSA. Briefed specifically to create a competitive parallel-twin, the internally designated A10 model was based on an earlier A7 design by Page and Bert Perkins. After BSA took over Triumph in 1951, Hopwood returned to Norton.Production
The large carry over of parts from the A7 had the advantage of greater reliability, as it minimised the risk of any new technical problems. Launched in a new form of gold colour, the combination of reliability and marketing made early exports possible, with 80% of production destined for the USA. The result was long delivery times for British customers, who were offered a more practical and less stand out black.Although never designed as a fast machine, the Golden Flash was none the less fast for its time and competitive with the Triumph 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...
, achieving over 100 miles per hour (160.9 km/h) in tests in 1950, and covering a standing quarter mile in under 16 seconds. Its gold colour also made it a marketing and sales success, out selling the red Speed Twin and the later blue-grey Triumph 6T Thunderbird
Triumph Thunderbird
The Triumph Thunderbird is a British motorcycle that was introduced by Triumph in 1949 and produced in its original form until 1966. The name was used three more times for new and distinct Triumph models.-Original model:...
, which was resultantly revised the following year into polychromatic blue.
However, BSA were concerned about a tendency for wear in the rear, plunger suspension, leading to uncertain handling. In 1954 it revised the model with a modern swinging arm, and the hinged mudguard was deleted. The semi-unit power train was also abandoned, making for a more involved procedure for adjustment of the primary chain, it offered benefits in the areas of the clutch and gearbox internals. The revisions also allowed for the launch of more sporting A10 Road Rocket.
In 1956, alloy brake drums were fitted as standard which both reduced unsprung weight and increased stopping power.
BSA Super Rocket
The BSA Super Rocket was a Birmingham Small Arms Company motorcycle that was a development of the BSA Road Rocket that evolved from the Golden Flash...
was launched for the 1958 season, with an Amal TT carburettor and high lift cam.
The final A10 development, and fastest in terms of power and performance, the 1962 BSA Rocket Gold Star
BSA Rocket Gold Star
The BSA Rocket Gold Star is a British motorcycle that marked the final stage of development of the BSA A10 twins. With a specially tuned A10 Super Rocket engine in the well proven BSA Gold Star single frame, BSA created a very fast bike with good handling fast bike that became 'classic'...
, which fitted a tuned A10 Super Rocket engine into the well proven BSA Gold Star
BSA Gold Star
The Gold Star is a motorcycle made by BSA from 1938–1963. They were 350 cc and 500 cc single-cylinder four-stroke production motorcycle known for being among the fastest bikes of the 1950s...
single frame. The result was a good handling fast bike that was a true classic. Current demand for the Rocket Gold Star, or "RGS", is such that non-RGS A10s are sometimes sold as originals, having been modified using suitable alternative parts.
With the launch of the new unit-construction (combined engine/gearbox) BSA A50 and BSA A65, the A7 and A10 were discontinued at the end of 1962 but the Rocket Gold Star continued into 1963 production.
Further reading
- Bacon, Roy, BSA Twins & Triples The postwar A7/A10, A50/65 and Rocket III, Osprey, 1980.