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BSA Golden Flash
BSA Golden Flash
BSA Golden Flash
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BSA A10 Golden Flash
1950s Golden Flash with headlamp cowl and swinging arm rear suspension
ManufacturerBirmingham Small Arms Company (BSA)
Also calledA10
Production1950–63
AssemblySmall Heath, Birmingham, UK
Predecessornone
SuccessorBSA A65 Star
Engine646 cc (39.4 cu in) air cooled twin
Bore / stroke70 mm × 84 mm (2.8 in × 3.3 in)[1]
Power35 bhp (26 kW) @ 4500 rpm[2]
Ignition typeMagneto
Transmissionfour-speed gearbox to chain drive
SuspensionTelescopic fork (front), rigid plunger swinging arm (rear)
BrakesDrum
Wheelbase1,391 mm (54.75 in)
DimensionsL: 2,100 mm (84 in)
Weight179 kg (395 lb)[3] (dry)
Fuel capacity3.5 imp gal (16 L)

The BSA Golden Flash, commonly misnamed the Gold Flash,[4] was a 646 cc (39.4 cu in) air-cooled parallel twin motorcycle designed by Bert Hopwood and produced by Birmingham Small Arms Company (BSA) at Small Heath, Birmingham. The Golden Flash was the first model in the BSA A10 series. It was available in black and chrome; but it was the distinctive golden paint scheme that gave The Golden Flash its name. Production continued until 1963,[5] when it was superseded by the BSA A65 Star.

Development

[edit]

Background and development

[edit]

Bert Hopwood served an apprenticeship under designer Val Page at Ariel. In 1936, Hopwood moved to Triumph, where he worked under Edward Turner to develop the 1937 Triumph Speed Twin. The innovative Speed Twin became the exemplar of the parallel twin engine layout for British motorcycles in the 1950s and 1960s. In April 1947 Hopwood joined Norton to design the Norton Dominator engine.

BSA, then the largest UK motorcycle manufacturer, was falling behind in the parallel-twin race. Although BSA had a parallel-twin, the BSA A7, they needed to develop the bike to remain competitive. In May 1948, the factory enticed Hopwood after only a year at Norton,[6] and he was commissioned to create a competitive BSA parallel-twin.[7][8] Launched in October 1949, Hopwood's A10 Golden Flash drew heavily from the A7 design by Page and Bert Perkins.[9]

Early A10 Golden Flash with plunger rear suspension and semi-unit engine and gearbox. The gearbox is bolted to the rear of the engine. Rear suspension was originally optional.

The A10 was increased to 650 cc (40 cu in), with a revised alloy rocker box and cast-iron cylinder head, plus an integral manifold for the single Amal carburettor. A semi-unit gearbox meant the primary chain was adjustable via a slipper tensioner within the primary chain case. The frame was available in rear rigid format, but the more common option was plunger suspension, adopted for the export market.[10] The A10 featured a hinged rear mudguard to ease rear wheel removal. The A10 was so closely based on the A7 that it used many of its well-proven components, and this large carry-over of parts from the A7 promised greater reliability, with minimal risk of new technical problems.[9]

Early cast Golden Flash tank badge

Production

[edit]

The BSA Golden Flash was launched in a new gold colour, and 80% of production was destined for the United States. This resulted in long delivery times for British customers, who were offered the model only in black.[11]

Although never designed as a sport motorcycle, the Golden Flash was nonetheless fast for its time and competitive with the Triumph Tiger 100, achieving over 100 miles per hour (160 km/h) in tests in 1950, and covering a standing quarter mile (400 m) in under 16 seconds.[12] Its gold colour proved a marketing success, outselling Triumph's Speed Twin and 6T Thunderbird.

BSA were concerned that wear in the plunger suspension was leading to uncertain handling. In 1954 the factory adopted a swinging arm,[13] and the hinged mudguard was deleted. In a seemingly backwards step, the semi-unit gearbox was abandoned for a separate "pre-unit" item. The new design had a different primary chain adjustment, a modified clutch, and new gearbox internals.

A tuned version. the Super Flash was available in the US in 1963 - 1964. Following requests for a more powerful version from the US, the engine was turned with parts from the competition department. This was an interim measure whilst sports bike version of the A10, the Road Rocket was being developed.[14]

Later A10 Golden Flash, about 1961, with separate engine and gearbox; headlamp nacelle; swinging arm rear suspension; and "pear drop" BSA badges on either side of the fuel tank

In 1957 an improved clutch was introduced, using 4 springs instead of six and improved friction material.[4][15]

For better reliability, the Golden Flash was upgraded in 1958 to the "thick flange" cylinders (base flange increased from 3/8" to 1/2") and larger big ends originally fitted to the Road Rocket.[16]

For 1960 the model was fitted with the 356 sports camshaft[17] and a larger (1 1/8" bore) 389 Monobloc carburettor.[18] It was renamed the "Royal Tourist" in the US.[19]

An alternator was offered as an alternative to the dynamo from 1961 to 1963, the last three years of production.

In the late 1950s, motorcycle electrical component manufacturer Lucas decided to switch production from magneto/dynamo systems to alternators/coil systems. This forced British motorcycle manufacturers to completely redesign their engines. With the launch of the new unit construction (combined engine/gearbox) BSA A50 and BSA A65, the A7 and A10 were discontinued in 1963.

See also

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References

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Further reading

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[edit]
Revisions and contributorsEdit on WikipediaRead on Wikipedia

BSA Golden Flash

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from Grokipedia
The BSA Golden Flash, commonly misnamed the Gold Flash, is a classic British motorcycle model manufactured by the (BSA) from 1950 to 1963, featuring a 646 cc air-cooled, overhead-valve parallel-twin engine that produced 35 horsepower at 4,500 rpm. Designed by engineer as an upgrade from the preceding 500 cc A7 model, it was introduced in October 1949 with a focus on reliable performance for touring and daily use, achieving a top speed of approximately 100 mph. The model's distinctive name derived from its signature polychromatic golden beige paint scheme, which was applied to about 80% of units destined for export markets, particularly the . Produced at BSA's factory in Birmingham, , the Golden Flash formed the basis of the A10 series and was built in various configurations, including rigid, , and later swinging rear suspension frames. Early models from to used rigid or rear suspension with 8-inch front and 7-inch rear , while marked the shift to swinging suspension for improved handling, and introduced alloy drums for better stopping power. Weighing around 395 pounds dry and equipped with a 4-speed foot-shift transmission and 4-gallon , it offered a range of about 200 miles at 50 , making it suitable for long-distance travel. The Golden Flash competed directly with rivals like the and appealed to riders seeking a balance of power, comfort, and affordability in the post-World War II era, with tests confirming its capability for 100 mph-plus speeds. Production ceased in 1963 with the introduction of BSA's unit-construction A50 and A65 models, but the Golden Flash remains a sought-after classic today for its engineering simplicity and historical significance in British motorcycling.

Development

Background

Birmingham Small Arms Company (BSA) had established itself as a leading British manufacturer by the pre-war period, producing a range of singles and military-oriented models that emphasized reliability and capabilities. During , BSA shifted much of its focus to wartime production, supplying over 126,000 M20 solo to the Allied forces between 1937 and the war's end, alongside munitions and other components, which honed its engineering expertise but halted civilian model development. The A7, BSA's first parallel-twin , emerged as the direct predecessor to the Golden Flash; its design originated in under Val Page, with Herbert Perkins completing the 495 cc overhead-valve engine and overall layout post-war for a 1947 launch. Following the war, British motorcycle manufacturers like BSA faced severe economic pressures amid national reconstruction, including material shortages, labor constraints, and a government-mandated "export or die" to rebuild foreign currency reserves. , particularly to the , became critical, accounting for a significant portion of production as American demand surged for affordable, durable British twins to fill the leisure market. This orientation pushed BSA to prioritize models that could compete internationally, evolving from wartime utility to civilian touring bikes suited for long-distance American roads. In 1948, joined BSA as chief engineer, bringing experience from Ariel, Triumph, and Norton, and was tasked with modernizing the company's parallel-twin lineup to meet rising performance expectations. Hopwood's influence centered on refining the A7 platform, increasing the from 495 cc to 646 cc through revised bore and stroke dimensions to deliver greater power and torque for export markets. This evolution culminated in the 1949 launch of the Golden Flash, initially distinguished by its metallic gold paint scheme to appeal to style-conscious buyers.

Design Process

The design of the BSA Golden Flash was led by engineer , who joined BSA from Norton in 1948 and undertook a comprehensive redesign of the existing A7 parallel twin engine to create the A10 model. Hopwood's efforts focused on increasing displacement to better compete in the post-war motorcycle market, particularly against rivals like the , by adopting a bore of 70 mm and a of 84 mm, resulting in a 646 cc capacity. This configuration provided a balance of and power suitable for long-distance touring, while maintaining the overall architecture of the A7 for production efficiency. A distinctive feature of the Golden Flash was the introduction of gold-finished engine casings, achieved through a gold-like silver beige paint scheme on the components, which contributed to the model's premium aesthetic appeal. The name "Golden Flash" was derived from this eye-catching finish, chosen to attract export markets and evoke speed and luxury. With approximately 80% of early production directed toward the to capitalize on demand for reliable touring motorcycles, the design emphasized durability and visual distinction. The powertrain incorporated a newly developed 4-speed semi-unit gearbox bolted to the rear of the engine, paired with a duplex primary chain drive for smooth power delivery. Early prototypes underwent rigorous testing, achieving speeds exceeding 100 mph to verify reliability under load, with adjustments made to the chain tensioner for optimal performance. Complementing this was an enhanced air-cooling system with deep fins and dry sump lubrication, alongside the overhead valve (OHV) configuration featuring a single camshaft and pushrods, which improved breathing efficiency over sidevalve designs. These innovations targeted an output of 35 bhp at 4,500 rpm with a 7.25:1 compression ratio, prioritizing usable power for highway speeds.

Initial Launch

The BSA Golden Flash was officially announced in October 1949 at the company's factory in Birmingham, , marking the debut of BSA's new 650 cc parallel-twin designed for the post-war market. Priced at approximately £217 in the , the model was positioned for immediate availability starting in the 1950 season, though demand from exports—particularly to the , which accounted for 80% of production—resulted in extended wait times for domestic buyers. BSA's marketing emphasized the Golden Flash's enhanced speed capabilities and distinctive gold styling (with black variants for the market) to directly challenge competitors like the Triumph 6T Thunderbird, appealing to riders seeking reliable performance in a larger-displacement OHV twin. The initial production run began in , featuring a rigid frame with optional plunger rear suspension for improved ride quality over earlier designs. This engine represented an increase in displacement from the preceding A7's 500 cc unit, providing greater power for touring and export markets.

Specifications

Engine and Performance

The BSA Golden Flash was powered by a 646 cc air-cooled overhead-valve (OHV) parallel-twin engine, featuring a bore and stroke of 70 mm × 84 mm. This design, developed by , delivered 35 at 4,500 rpm, with an initial of 6.5:1 that was increased to 7.25:1 in later models for improved efficiency. The engine's gold-painted casings contributed to the model's distinctive aesthetic from its inception. The drivetrain incorporated a four-speed gearbox with a final drive, providing reliable power transfer suited to long-distance touring. In period road tests, the Golden Flash achieved a top speed of 104 mph while demonstrating strong mid-range , capable of quarter-mile times around 16 seconds. Its torque output, peaking at approximately 35 Nm, emphasized smooth and progressive power delivery rather than peaky high-rev performance, making it ideal for sustained highway cruising. Fuel was supplied via a single Amal carburetor to a 3.5 imperial gallon (16 L) tank, enabling a practical range for extended journeys. The engine's efficiency yielded fuel economy of around 50 mpg under typical touring conditions, balancing performance with economical operation.

Chassis and Components

The BSA Golden Flash utilized a duplex cradle frame constructed from steel tubing, which provided robust structural integrity and supported the motorcycle's touring-oriented design. The front suspension employed telescopic forks, delivering smoother handling and better road absorption compared to rigid setups of the era. In later iterations, these forks were upgraded to Girling models, featuring improved oil damping for enhanced stability and rider comfort. Rear suspension on early models consisted of a plunger-type system, which, while functional, offered limited articulation over uneven terrain. This evolved to a swinging arm configuration in , significantly refining the bike's dynamics and contributing to its overall dry weight of 179 kg. Braking duties were performed by single-leading-shoe measuring 8 inches in at the front and 7 inches at the rear, adequate for the era's speeds and loads. The wheels featured a 19-inch rim up front shod with a 3.25 x 19 and an 18-inch rear rim with a 3.50 x 18 , balancing and load-carrying capability. The electrical system was based on a 6-volt setup with magneto ignition, ensuring reliable spark delivery without reliance on a battery for starting. From 1961 to 1963, an option became available, modernizing charging capabilities for accessories and . These elements, spanning the model's 1950–1963 production run, underscored the Golden Flash's emphasis on dependable, straightforward .

Production

Timeline and Changes

The BSA Golden Flash entered production in 1950 at BSA's works in Birmingham, , following its debut the previous year, and remained in manufacture until 1963. This pre-unit construction parallel twin became a staple of BSA's lineup, evolving incrementally to address rider feedback and market demands while maintaining its core 646 cc engine design. Significant mechanical refinements began in 1954 with the adoption of swinging arm rear suspension, which replaced the less stable setup and incorporated twin shock absorbers for enhanced road handling and comfort. By 1957, an updated design improved shifting smoothness through revised spring configuration and friction materials, reducing wear and operator effort. In 1961, an optional system was introduced to the electrical setup, offering greater charging efficiency over the traditional for better long-term reliability. Styling adjustments were made annually throughout the , with notable mid-decade revisions to fuel tanks—featuring centralized mounting and rounded badges—and seats to accommodate preferences in key export markets like the , where the model saw substantial demand. These cosmetic evolutions kept the Golden Flash visually competitive without altering its fundamental engineering. Production tapered off in the early as BSA faced intensifying rivalry from Japanese manufacturers, whose affordable, reliable imports eroded the British bike's market share and contributed to the model's phase-out in favor of newer unit-construction designs.

Export and Market Focus

The BSA Golden Flash achieved significant export dominance, with approximately 80% of production units shipped to the , where it was positioned as a dependable suited for long-distance American highway travel. This focus on the U.S. market stemmed from postwar demand for reliable, mid-capacity twins that could handle expansive road networks, leading to adaptations such as reinforced components to accommodate larger riders and extended touring setups. Key distribution networks in the U.S. were established through partnerships with major importers, notably Hap Alzina, the principal West Coast distributor for during the , who influenced design refinements based on American rider feedback to enhance comfort and performance for domestic conditions. These collaborations facilitated widespread availability through regional dealerships, emphasizing the model's gold color scheme—which was briefly referenced for its visual appeal in export models—to attract buyers seeking a premium, distinctive alternative to domestic options. Sales performance peaked during the , with substantial exports to the U.S. contributing to the model's global success over its run from 1950 to 1963. However, later years saw declining figures due to challenges including proposed U.S. increases on imported motorcycles—such as Harley-Davidson's 1952 push for a 40% duty, which heightened scrutiny on foreign competitors—and intensifying rivalry from established American brands like , whose larger V-twins dominated the heavyweight segment. These factors strained profitability and prompted BSA to adjust pricing and marketing strategies to maintain .

Variants and Successors

Key Variants

The Super Flash, produced in 1953 with a limited run of 577 units, represented a high-performance iteration of the A10 series, featuring a cast-iron cylinder head and alloy rocker box, a large Amal TT9 racing carburetor, and a tuned 646 cc engine delivering 40 bhp for enhanced speed and responsiveness. Primarily targeted at the US market, it included a triplex primary chain for durability under demanding conditions and required frame modifications to accommodate the carburetor. The Road Rocket, introduced in 1954, was a sporting variant with twin Amal carburetors, an alloy cylinder head from 1955, and increased power output approaching 40 bhp, aimed at performance enthusiasts. The Super Rocket, launched in 1957, further enhanced the series with a high-lift camshaft, Amal TT carburetor, and output of 43 bhp, achieving top speeds over 105 mph while retaining the 646 cc displacement. The Royal Tourist, marketed exclusively in the US starting in 1960, was the export name for the touring-oriented Golden Flash model, featuring the standard enclosed chaincase and optional accessories like legshields and windshields for long-distance comfort. This variant maintained the core 646 cc engine but emphasized reliability and ease for American highway use. Production continued through 1963 alongside the standard model. Minor variants included early export A10 models equipped with western-style high-rise handlebars (part number 42-4968) to suit American riding preferences and , often seen on units shipped abroad. Late Golden Flash models also offered optional fairings for improved and weather protection during extended rides. These changes, such as accessory enclosures or ergonomic adjustments, set them apart from the base model's simpler setup without altering core mechanical specifications.

Transition to Successors

The production of the BSA Golden Flash concluded in 1963, as the model was discontinued alongside the broader A10 pre-unit construction series in favor of newer unit-construction designs, a shift prompted by the rising dominance of Japanese manufacturers offering more reliable and cost-effective motorcycles in the global market. This transition was led by the introduction of the BSA A65 Star Twin in 1962 as the direct successor, which adopted an integrated engine and gearbox configuration with a 650 cc parallel-twin displacement to address the limitations of the outdated pre-unit architecture that had defined the Golden Flash. The obsolescence of the Golden Flash's separate engine and transmission setup, coupled with BSA's post-1951 merger with Triumph—which facilitated greater rationalization across the combined lineup—underscored the need for modernization to remain viable amid intensifying international competition. The final 1963 production run marked the end of the pre-unit A10 series before its full phase-out.

Reception

Contemporary Reviews

Upon its introduction in late , the BSA Golden Flash received positive attention in road tests for its performance capabilities, with one early evaluation recording a top speed of 105 mph. Reviewers praised the motorcycle's smooth power delivery from its 646 cc parallel-twin , producing 35 bhp, which made it suitable for comfortable touring at highway speeds. However, critics noted noticeable at high engine revs, a common trait of the vertical-twin configuration that could fatigue riders during extended fast runs. The Golden Flash was competitive with contemporaries like the for long-distance touring, offering similar outright speed and stability, though it was less agile than lighter single-cylinder models like the in twisty conditions. The motorcycle's reliability and sturdy construction appealed to riders, including those seeking dependable transport for extended journeys. Common criticisms centered on the motorcycle's heavy weight, around 400 pounds dry, which compromised handling on uneven surfaces and made maneuvering at low speeds more demanding compared to nimbler rivals. Despite these drawbacks, testers highlighted its strong , retailing for approximately $975 in the US market. The model garnered significant magazine coverage in the and early 1960s, with features in The Motor Cycle detailing its engineering refinements and in Cycle World showcasing its appeal to American enthusiasts, often underscoring its role in BSA's growing export success to .

Modern Legacy

The BSA Golden Flash maintains a dedicated following among collectors, with restored examples from the commanding values typically ranging from $5,000 to $15,000 at , influenced by condition, , and . For instance, Hagerty valuations as of 2025 list a #3 Good condition 1955 model at $6,400, while a 1959 survivor was listed at $11,500. A 1962 model sold for $7,700 at in January 2024. These motorcycles are particularly popular at vintage rallies, such as the annual Barber Vintage Festival in , where Golden Flashes are displayed in the museum's extensive collection and ridden in period-appropriate events alongside other classic British bikes. Restoration efforts highlight the model's enduring appeal but also its challenges, as many original parts for the A10 series are scarce after the production run ended in 1963. Specialists like Draganfly Motors provide essential new, reproduction, and NOS components, including engine parts, electrical fittings, and chassis hardware, enabling comprehensive rebuilds. A frequent hurdle is the original 6-volt electrical system, prone to charging inconsistencies and lighting failures, often addressed through upgrades to 12-volt alternators and electronic ignition for modern reliability. The Golden Flash's design has left a mark on custom bike culture in the and , inspiring builders to adapt its robust 646 cc parallel-twin engine for scramblers, cafe racers, and bobbers, blending vintage aesthetics with contemporary modifications. Although BSA's was revived in the under Mahindra ownership, culminating in the 2021 launch of a new Gold Star model, this effort did not extend to reissuing the Golden Flash; heritage preservation instead relies on enthusiast organizations like the BSA Owners' Club, which supports restorations, rallies, and technical resources for A10 owners worldwide.

References

  1. https://www.motorcyclespecs.co.za/model/BSA/BSA%20A10%20Golden%20Flash.htm
  2. https://www.topspeed.com/motorcycles/motorcycle-news/pristine-1953-bsa-a10-golden-flash-becomes-museum-piece/
  3. https://british-classic-motorcycles.co.uk/index.php/bsa-a10/
  4. https://www.bsacompany.co.uk/history/
  5. https://www.real-classic.co.uk/2016/11/25/bsa-a7/
  6. https://www.classicbikeguide.com/bsa-a7/
  7. https://www.ianchadwick.com/motorcycles/britbikes/index.html
  8. https://magazine.cycleworld.com/article/1976/9/1/demise-of-the-british-industry
  9. https://cybermotorcycle.com/people/bert-hopwood.htm
  10. https://www.hagerty.com/valuation-tools/bsa/a10_golden_flash/1959/1959-bsa-a10_golden_flash
  11. https://sump-publishing.co.uk/bsa%20golden%20flash.htm
  12. https://www.historics.co.uk/auction/lot/367-1955-bsa-golden-flash/?lot=10979&sd=1
  13. https://nationalmotormuseum.org.uk/collections/vehicles/bsa-a10-golden-flash/
  14. https://cybermotorcycle.com/marques/bsa/bsa-a10.htm
  15. https://www.motorcycleclassics.com/classic-british-motorcycles/classic-bsa-motorcycles/1960-bsa-a10-zm0z22mjzram/
  16. https://www.autoevolution.com/moto/bsa-a-10-golden-flash-1949.html
  17. https://www.british-classic-motorcycles.co.uk/index.php/bsa-a10/
  18. https://fastestlaps.com/models/bsa-a10-golden-flash
  19. https://cybermotorcycle.com/gallery/bsa-1963/
  20. https://deeleyexhibition.ca/brief-history-bsa/
  21. https://www.jetsforever.com/hap-alzina
  22. https://www.britbike.com/forums/ubbthreads.php?ubb=showflat&Number=426330
  23. https://bringatrailer.com/listing/1953-bsa-super-flash/
  24. https://classicavenue.com/product/1953-bsa-650cc-super-flash-serial-no-001-copy/
  25. https://bid.hendersonauctions.com/ui/auctions/69696/6311462
  26. https://www.artcurial.com/en/sales/6144/lots/381-a
  27. https://www.feked.com/bsa-handlebars-a7-a10-a65-western-style.html
  28. https://gpcycleworks.com/products/fairing-manufacturer-bsa-golden-flash-royal-1960
  29. https://www.topspeed.com/motorcycles/motorcycle-news/what-really-happened-to-the-british-motorcycle-industry/
  30. https://www.webbikeworld.com/bsa-motorcycles/
  31. https://www.devittinsurance.com/blog/need-know-bsa/
  32. https://www.britbike.com/forums/ubbthreads.php/topics/38029/bsa-a10-a65-performance-comparo
  33. https://www.ebay.com/itm/195604582695
  34. https://www.hagerty.com/valuation-tools/bsa/a10_golden_flash/1955/1955-bsa-a10_golden_flash
  35. https://www.classicmotorcycleconsignments.com/products/1959-bsa-golden-flash-original-survivor
  36. https://www.mecum.com/lot_detail.cfm?lot_id=1110809
  37. https://www.barbermuseum.org/collection/
  38. https://draganfly.co.uk/product-category/bsa/
  39. https://www.stotfoldengineers.co.uk/stotfold-engineering-blog/2016/03/17/1950-bsa-a10-golden-flash/
  40. https://www.bike-urious.com/restored-1956-bsa-golden-flash/
  41. https://www.advrider.com/bsa-returns-with-the-gold-star/
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