BSA Motorcycles

BSA emblem

When BSA Motorcycles Ruled the World

From the mid-1930s through the early-1960s, BSA was the world's largest producer of motorcycles. BSA owned Triumph, Ariel, Sunbeam and New Hudson Motorcycles, along with factories that made steel, built cars, buses, heavy construction equipment, agricultural and industrial power plants, machine tools, weapons, ammunition, military equipment, bicycles and even had its own steel mill. BSA was a bona fide industrial giant, capable of accomplishing almost anything and in far better financial shape than just about anyone else in the motorcycle business at that time. By 1960, the BSA Gold Star was a mega hit, on the track and in showrooms, and BSA’s A7 (500) and A10 (650) non-unit twins were solid sellers with a great reputation, even the tiny 2-stroke Bantam was selling like hotcakes. Yet by 1972, BSA was broke, out of business and irrelevant as a motorcycle company. What happened?

Swords to Plowshares

BSA started out as a loose alliance of 16 small craftsmen shops in the Coventry area of England who teamed up to produce rifles for the British Army during the Crimean War (1853−56), in the days when firearms were painstakingly handcrafted by artisans. They soon realised that two things would be needed for their survival: modern production techniques and a broader product line. By 1884, BSA was building bicycles, a new thing at the time and all the rage. From there they graduated up to motorised bicycles, then true motorcycles by 1905. At a time when most motorcycle manufacturers were 'cottage industries' that relied on parts brought in from outside suppliers (i.e. engines, gearboxes, and wheels, etc.), BSA was already so big that it was making virtually everything for its bikes in-house.

1929 BSA Sloper

This 1929 BSA S29 Twin Port shows why these bikes were nicknamed ‘Slopers’ − because of the pronounced angle of its cylinder.  

BSA Motorcycles in World War 1

World War I was good for BSA. Not only did they sell lots of motorcycles to the British Army, by the war's end they were producing 10,000 Lee-Enfield .303 rifles PER WEEK! They also built 145,000 Lewis machine guns. After the war, BSA went back to building reliable, workhorse motorcycles, not necessarily the fastest or the sexiest. They introduced a new OHV 493cc single called the ‘Sloper’ (because of the sloped angle of the cylinder) in 1926. They developed a line of V-twins to serve the burgeoning sidecar market and continued to refine their big singles, including a new 500 in 1937 called the Empire Star, which morphed into the legendary BSA Gold Star.

1956 BSA Gold Star

This 1956 BSA DBD34 Gold Star 500 was obviously the street version. However, 'Goldies' also ruled off-road competitions of every type as well as road racing, well into the early 1960s. 

BSA Gold Star

The BSA Gold Star, in both 350cc and 500cc displacements, was an instant hit, on the streets, off-road, on race tracks and in showrooms. The big, all-alloy pushrod single was advanced for its day, robust and very fast. Gold Stars were special from the start, every engine hand-built, then dyno-tested, with the printed results included with every brand new bike. By the time production ended in 1963, the Gold Star had dominated road racing in Europe and scrambles, desert/off-road racing and even motocross in the US for well over a decade. The dawn of the lightweight 2-stroke spelled the end of the Gold Starʼs relevance as a dirt bike. Unlike Triumph, who managed the switch to unit construction in 1963, BSA didnʼt do nearly as well. The Gold Star was one of the casualties. Also, Lucas Electrics (nicknamed 'The Prince of Darkness' because of their sketchy reliability) was discontinuing production of the magneto that the ancient Gold Star required. So, BSA Gold Star production ended in 1963 only to be replaced by the new, unit-construction BSA 441 Victor, a bike that never achieved the same success on the track on in showrooms, nor did it have the Goldie's cache.

1952 BSA A7

This 1952 BSA A7 was BSAʼs 500cc entry-level twin. Itʼs a good representation of what BSA was building in the early 1950s. 

BSA Motorcycles in World War 2

When Triumph introduced its seminal 500 Speed Twin in 1937, it set the British motorcycle industry on fire, and most of that industry, those who could afford to, rushed to market with their own vertical twins. But World War II put all of that on hold. Not bad for BSA though, who not only sold 130,000 M20 side-valve bikes to the Army, it was back to churning out endless Lee-Enfield rifles, plus (at its peak) 16,390 Browning machine guns per month!

1939 BSA M20

This 1939 BSA M20 is a prime example of the boatloads of military bike that BSA produced for the King's Army during World War 2.

BSA Motorcycles gets a Vertical Twin

When civilian production resumed in 1946, BSA introduced its own 500cc vertical twin, the A7, chasing after Triumph's 1938 5T Speed Twin. They followed it up four years later with an ‘enlarged’ 650 version called the A10, meant to compete with Triumph's own 'enlarged' 650cc 6T Thunderbird. Both BSAs were handsome machines that performed well and sold like hotcakes until they were replaced by the unit-construction A50 and A65 in 1962. This was indeed BSAʼs Golden Age.

BSA Motorcycles is a True Industrial Giant

BSA Motorcycles acquired Ariel in 1944, then Triumph in 1951, both from the seller, Jack Sangster who came along with the deal. He sat on BSAʼs board of directors until the early 1960s and oversaw the stripping and selling-off of BSAʼs assets. By the time he retired, the once mighty industrial giant was a pitiful shadow of its former self. Not only were the money and all the assets gone, but much of the talent had left also. As a result, BSA made a string of blunders in the 1960s that hastened its trip to the grave.

1967 BSA A65 Lightning

This 1967 A65 Lightning 650 shows why the A65 from this era was considered the ultimate BSA twin. It was BSA's twin-carb answer to the ʻBonnevilleʼ.

The 60's Weren't Good to BSA Motorcycles

In 1962, BSA re-engineered its entire line of twins, replacing the highly-successful non-unit construction A7 and A10 with the ungainly, but unit-construction A50 (500) and A65 (650) twins. They werenʼt nearly as pretty as the bikes they replaced and never really sold as well. The once-elegant engines lost some of their rugged handsomeness, perhaps to their detriment, depending upon ones tastes. BSA applied the same treatment to the Gold Star line with similarly disappointing results. Sales just got worse and worse. Triumphs, however, were flying off the shelves, especially in America. BSA owned Triumph and should have been celebrating, but instead it resented Triumph’s success and treated the company poorly. Business went from bad to worse. What to do? The brilliant minds at BSA decided the answer was a new multi-million-pound research center in a lavish English country estate called Umberslade Hall.

Not only could BSA not afford it, but Umberslade produced almost nothing of value. A 350 twin that was never produced and the reviled ‘oil-bearing frames’ introduced on 1971 BSA and Triumph twins were examples of the inept thinking within the elegant walls of Umberslade Hall. Instead of fixing the vibration, oil leaks, shoddy electrics, poor reliability, and a complete line of outdated engines, they chose to build a new frame, which was the least of their problems. They never actually tested it though, so when the new frames hit the production line, they discovered that Triumphʼs engines wouldnʼt fit! Really?! The rear rocker boxes needed to be removed before the engines would slide into place in the frame. Then, the rocker boxes needed to be reinstalled, all on the production line! Thank you, Umberslade Hall.

BSA Engine Comparison

LEFT: The pre-1962 non-unit construction 650cc BSA A10 had a separate crankcase, primary case and gearbox all bolted together with brackets. RIGHT: It was replaced by the unit construction 650cc A65, with everything packaged in one common casing. BSA called it ‘The Power Egg’. 

BSA Motorcycles Switch to Unit Construction

Until this time, most motorcycles had separate engines and gearboxes, connected by a primary chain case, all held together with a system of brackets. This was called non-unit or pre-unit construction. Unit construction consolidated all three components into one unitized casing, hence the name.

Unit construction was all the rage in Britain in the late 1950s. Vincent did it first, back in 1946, with the Series B Rapide and Black Shadow. But, Triumph was the first of the major players to switch, with the 1959 3T 350 twin, and it quickly spread to the 5T 500 twins. Triumph didnʼt switch the 650 twins out until the 1963 model year. This made only some sense, as all the twins (500 and 650) shared the same architecture in the pre-unit days. The 500 was stretched into a 650 in 1950. But the new unit-construction twins would now split into two distinctly different engine families: the 350 and 500 twins were in one family, and the large 650s were alone in the other. Triumph did a good job of styling these new engines to remain faithful to the look it had established with their non-unit engines. Both were clearly Triumphs. BSA chose not to follow this logic. Instead they completely restyled their engines, taking all the curvaceous shape out of it and turning it into an amorphous blob that they called ‘The Power Egg’. They managed to make both sides of the engine look the same, very unusual for a heavyweight motorcycle engine. It surely cost BSA a fortune to make the switch from non-unit to unit construction. Perhaps they should have chosen, as Triumph did, to remain faithful to their well-established and well-accepted brand character.

The new A50 500cc unit-twin launched in 1962, with the A65 650cc unit-twin one year behind in 1963. There was actually some overlap during this time where both unit and non-unit machines were built. The early unit engines had problems with bearings and bushings, but that was sorted out quickly enough, making them pretty good engines, by the standards of the day. Their early reliability issues hurt sales, and the unit-construction twins never quite sold as well as the pre-unit bikes in the US. Despite all this, throughout most of the 1960s, the BSA 650 was regarded as one of the fastest motorcycles money could buy, topped by the twin-carb A65 Lightning.

1969 BSA Rocket 3

When introduced in 1969, the 750cc BSA Rocket 3 triple was fast, but homely. Check out the ‘shoebox gas tank’ and those crazy ‘ray gun’ mufflers!

BSA & Triumph Triples

Perhaps the last gasp was the introduction of the BSA Rocket 3 and the Triumph Trident, both 750cc 3-cylinders. Conceived in 1962 by Triumphʼs Bert Hopwood, the triple used three sets of the BSA/Triumph 250 hardware, and by 1965, prototypes showed great promise. Triumph wanted to come out with the bikes in 1966 as a ʼ67 model, a move that would have changed history. But stubborn BSA didnʼt want Triumph to have that much credit, so they slow-walked the project until 1968 when it became known that Honda was coming out with their game-changing 4-cylinder 750. BSA then stepped on the gas and rushed the triples to production to try to beat Honda to market. However, BSA insisted that Triumph build a slightly different engine for BSAʼs triple, so they wouldnʼt look alike.

Triples engine comparison

The Triumph Trident (left) and the BSA Rocket 3 (right) had nearly identical engines, internally, but BSA insisted on a different look, so its cylinders slant 12-degrees forward, where the Triumph’s cylinders are vertical.  

The solution: the Trident has vertical cylinders and the Rocket 3ʼs are slanted slightly forward. Who cares, right? But that little change took time and money that BSA didnʼt have. Alas, they beat the Honda 750 Four to market by only four months, not nearly enough time to establish themselves. And, because of the currency exchange rate between the US and the UK, the triples were more expensive than the big Honda, which came with an electric starter, a 5-speed gearbox, and a front disc brake. And at first the new Triples were very ugly. BSA hired automotive firm Ogle to style the bikes, and the result was ghastly! A ʻshoeboxʼ gas tank and ʻray gunʼ mufflers dominated the look, nicknames given to them by the public. They never sold in great numbers. By 1970, both Triumph and BSA had straightened out the styling issues, and the triples were turning into great motorcycles. They were handsome machines that handled very well, and they were very fast. In 1969, a Trident out-accelerated the CB750 in a magazine test. Alas, the last BSA Rocket 3 was produced in 1971 as BSA struggled to survive. Trident production continued on the same Small Heath production line that both bikes had shared. The Trident was completely redesigned for the 1975 model year, now, finally, with electric start, and slanted cylinders, but it proved to be its final year.

1971 BSA A65 Lightning

BSA redesigned its 650 twins in 1971, at the same time as Triumph.  Their big twins both shared the same oil-bearing frame, along with most of the new running gear that gave them a more modern look.  This is a 1971 BSA A65 Lightning 650.

BSA Motorcycles' Last Gasp

By 1971, the entire British motorcycle industry was either dead or on life support. BSA Motorcycles merged with the only other British motorcycle company still standing, Norton-Villiers (formerly AMC) in an attempt to gain some strength. It didn’t work. The last BSA motorcycle was built in 1972. Norton continued to build Commandos (now its only model) until 1975. Norton now owned Triumph and tried to shutter Triumphʼs hallowed Meriden factory complex to move Triumph production to Nortonʼs own factory in Donington Park, a move intended to trim costs. Triumphʼs factory workers revolted in 1974, blockaded themselves inside the factory for nearly a year until a settlement was reached forming the worker-owned Meriden Co-op. They were undercapitalised from the start and struggled on, producing low numbers of Bonnevilles (now its only model) until 1983. Today, BSA is still in business, producing air rifles, rifle scopes and optical equipment.

1972 BSA Gold Star 500SS

This 1972 BSA Gold Star 500SS typified BSA’s big singles from that era. They were still considered competitive by some; they were certainly fast and handled well. These were some of the last bikes built by BSA before they shut their doors. 

New BSA Motorcycles from India

In 2016, the BSA brand was purchased by Mahindra, the worldʼs largest producer of tractors, with plans to produce new BSA motorcycles in India by 2019. As the tractor giant soon learned, its not that easy to launch a new motorcycle brand.  It took longer and cost much more than expected, but they launched their first new BSA-branded bike in 2022.  While built in India, Mahindra tried to remain faithful to classic BSA DNA.  Assuming sales hold up, Mahindra plans to expand the BSA brand's lineup and broaden its markets. 

2022 BSA Gold Star

This is the 2022 BSA Gold Star.  Designed by tractor-giant Mahindra and produced in India, the new Goldies are watercooled, note the radiator, and are thoroughly modern.

BSA Motorcycles - Models

Gold Star 500

Unit-Construction Singles

A7 500 Twin

A10 650 Twin

A65 Lightning

A65 Thunderbolt

Rocket 3

BSA Motorcycle Books


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