Matchless G12

The Matchless G12 is a British motorcycle made by Associated Motorcycles at the former Matchless works in Plumstead, London. Developed in 1958 specifically to capture the potentially lucrative US market, the last G12 was produced in 1966.

Manufacturer:Associated Motorcycles Plumstead, London Also called:'Monarch' Production:1958 - 1966 Predecessor:Matchless G11 Engine:646 cc (39 cu in) air cooled twin Power:35 bhp (26 kW) @ 6,500rpm Transmission:Four speed gearbox to chain final drive Brakes:drum brakes Weight:396 pounds (180 kg) (dry).

Development
Matchless G12
The Matchless G12 was one of the last motorcycles under the Matchless name and was also produced as the AJS Model 31 by the same company. Designer by Phil Walker, AMC knew that it had to be a 650 cc (39.7 cu in) but wanted to use as many parts from the Model 11 as possible. The cylinders could not be bored out further so the stroke was lengthened from 72.8 to 79.3 mm (2.87 to 3.12 in), resulting in a capacity of 646 cc (39.4 cu in). This meant developing a new crankshaft and primary chaincase, which also provided the opportunity to add a Lucas alternator. Volume production began in September 1958.
Matchless G12 De Luxe
In 1959 the G12 was redesigned and modernised as the De Luxe with a new full cradle tubular duplex frame and a new cylinder head. Vibration had always been a problem, so the crankshaft was upgraded to nodular iron. Capable of 100 mph (160 km/h) performance, the G12 became popular with the American market.
Matchless G12 CS
The Matchless G12 CS (sometimes referred to as the CS X) was an off-road version of the Matchless G12 with improved ground clearance and a slightly upswept exhaust and an 8.5:1 compression ratio. It was not a trials competition machine but instead aimed at the 'desert racer' market in the US.
Matchless G12 CSR
The Matchless G12 CSR designation officially stood for "Competition/Sprung/Roadster," the same nomenclature used with the G80 and G50 models. It is mistakenly referenced as Competition/Sport/Road. It was dubbed the Coffee Shop Racer by its rivals. With its distinctive two-into-one 'siamese' exhaust system and upgraded camshafts the CSR was a high performance motorcycle with what was, at the time, a high compression ratio of 8.5:1, distinguishing it and the G12 CS from the other G12 models, having a 7.5:1 compression ratio. The factory diverted Chief Engineer Jack Williams from AJS 7R development to address the problems with leaks and vibration and modify the bikes for racing - with the result that Ron Langston and Don Chapman won the prestigious Thruxton 500 long distance endurance race on the AJS Model 31 counterpart to the G12. Encouraged by this victory in 1963 the G12 CSR gained the name Monarch and twin carburettors (the AJS version was renamed the Hurricane).
Matchless G15/45
In 1964 the CSR gained Norton brakes and forks, and the following year a Norton Atlas 750 cc (45.8 cu in) engine replaced the trouble prone AMC unit. In 1962 and 1963, AMC had produced a limited run of 212 touring motorcycles of 738 cc (45.0 cu in) displacement using an enlarged version of the G12 AMC-designed engine, but these bikes—which were given the model designation "G15/45"—proved even less reliable than the 650 cc (39.7 cu in) version when ridden hard. So AMC's original plans to develop a 750 cc desert racer version were abandoned. If successful, this could have saved the company as there was a huge un-met demand in the US for powerful desert racers to compete in endurance events. By this time the company were in financial trouble and production ended in 1966.

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BSA Rocket 3

For full detail see BSA Rocket 3/Triumph Trident (for corresponding Triumph models see Triumph Triples)



The BSA Rocket Three / Triumph Trident was the last major motorcycle developed by Triumph Engineering at Meriden, and was a 750 cc air-cooled unit construction pushrod triple with four gears and conventional chassis and suspension. It was badge-engineered to be sold under both the Triumph and BSA marques.
The Rocket3 / Trident was part of Triumph's plan to extend the model range beyond their 650 cc parallel twins. Created to meet the demands of the USA market, the smooth 750 cc three-cylinder engine had less vibration than the existing 360° twins. BSA fell into serious financial troubles,but during the seven-year production run 27,480 Rocket3 / Trident models were produced.
Although designed in the mid-1960s, the BSA Rocket3 / Triumph Trident engine had its origins in a 1938 parallel twin, the 500 cc Triumph Speed Twin of 1937 designed by Edward Turner. The 1938 Tiger 100 was a sports version of the Speed Twin, and in essence the Trident three-cylinder engine is a “Tiger 100 and a half” (although the triple has a longer stroke than the "squarer" Tiger 100 engine).
Following Triumph tradition, the OHV Trident engine has separate camshafts for inlet and exhaust valves.
USA specification BSA Rocket 3 with the controversial Ogle styling.
The three-cylinder design was started in 1962 by Bert Hopwood and Doug Hele. Meanwhile, test engineers developed the handling of the chassis by affixing lead weights onto a standard 650 Bonneville. The first prototype, P1, was running by 1965, and it seemed that Triumph might have a machine in production by 1967. However, the decision to produce a BSA version with sloping cylinders and to employ Ogle Design to give the early Tridents / Rocket 3s their 'square tank' look not only robbed the prototype of its lean looks and added 40 lb (18 kg) of weight, but also delayed production by 18 months.[3] During 1966, a P2 prototype was produced with a more production-based Trident engine, with changed bore and stroke dimensions and improved cooling. Ultimately, Hele obtained 90 bhp (67 kW) from a Trident engine, leading to speculation that if development had sped up in 1964, a 140 mph (230 km/h) British superbike could have been a reality in 1972.
Although most British motorcycles used a wet multiplate clutch, this triple had a dry single-plate clutch sited in a housing between the primary chaincase and the gearbox. Mounted on the end of the gearbox mainshaft where one might expect to find the clutch there was instead a large transmission shock-absorber.
All the three-cylinder engines, and the Rocket 3 motorcycles, were produced at BSA’s Small Heath site, but final assembly of the Triumph Trident model was carried out at Meriden in Coventry.
The major differences were the engine and frame: The BSA had an A65-style double-loop cradle frame (with engine mounted at a slant), while the Triumph had a Bonneville-style single downtube frame with vertical cylinders.
Other differences were cosmetic. Triumphs sold better in the US despite BSA’s Daytona racing successes of the early 70s. However sales did not meet expectations, and for the 1971 model year a fifth gear was added, creating the models BSA A75RV and Triumph T150V.
BSA were having financial difficulties, and only some 205 five-speed Rocket 3s were built before production of the BSA variant ceased. Production of the five-speed Triumph T150V (with a front disc brake replacing the original drum) continued until 1974. For the 1975 model year the Trident was updated to the T160.

Model	Engine	First year	Last year	Notes
A75R Rocket Three	750 cc	1969	1972
A75RV Rocket Three	750 cc	1971	1972	5-speed gearbox (only three produced in 1972)

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BSA V-twins

V-twins
The BSA Model E was a British V-twin motorcycle manufactured by Birmingham Small Arms Company (BSA) at their factory in Armoury Road, Small Heath, Birmingham from 1919. It was often used with the matching BSA sidecar.

Development
After having been turned over to weapons production for World War I, BSA returned to producing motorcycles again which were sold as affordable with reasonable performance for the average user. BSA stressed the reliability of their machines, the availability of spares and dealer support. The BSA Model E was the first of a series of successful V-twins based around the reliable 770cc side valve engine with cylinders at an angle of 50 degrees. The modest 6hp produced by the engine was able to provide a top speed of 55mph and it had BSA's own design of three speed gearbox with the drive chain enclosed in an aluminium casing. There was an increased demand for affordable transport after the end of the war and the Model E became popular with BSA's matching green and cream painted sidecar option. Designed for easy servicing the valves were interchangeable and had quickly adjustable tappets. The constant loss oil pump was supplemented by a hand operated pump and the wheels were also quickly detachable and the same size so that they were interchangeable. Although the BSA Model E was produced until 1924 it had been largely replaced by the more powerful 986cc Model F in 1922, which continued in production as the BSA Model G, with continual modifications, until just after the outbreak of World War II.
V-Twins BSA Model:

Model	Engine	First year	Last year	Notes
Model E	771 cc	1919	1924	side-valve V twin
G30-G35	985 cc	1930	1935	side-valve
G14	985 cc	1936	1940	side-valve
J34, J35, J12	499 cc	1934	1936	overhead valve
Y13	748 cc	1936	1938	overhead valve

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Military Motorcycles Category

1. Ariel W/NG 350
The Ariel W/NG 350 is a motorcycle based on the well proven Ariel Red Hunter singles built by Ariel Motorcycles for the British military, and designed by the firm's chief designer Val Page in 1932 around an engine he developed six years earlier. Although the Ariel was not initially selected by the War Department, they were in great demand after the evacuation of Dunkirk when much of the British Army's materiel had been left behind.

Development
On the outbreak of the Second World War, Ariel submitted the 1939 VA 497 cc (30.3 cu in) overhead valve single for evaluation against the War Office's Norton 16H. The 1939 W/VA 497cc side-valve single was also tested. Both performed well and Ariel developed the W/NG specifically for military use. This was a 348 cc (21.2 cu in) OHV single based on a Scottish six-day Trials winning model and went into production in 1940.
Although the French military immediately placed orders for the W/NG, the British War Office rated it as "fair – for use only in emergency purposes". Following the loss of equipment resulting from the evacuation of Dunkirk in May 1940 the "emergency purposes" became necessary, and Ariel turned over as many motorcycles as possible to the war effort, including converted civilian machines – many of which still carried an Ariel badge painted over with green or sand paint. VH & VG (500 OHV singles), NH & NG (350 OHV singles), and even the VB (598 cc or 36.5 cu in SV single) models were put into military service, although most were used for training and civil defence.
The British Army, Royal Air Force, Admiralty, Ministry of Agriculture and Women's Land Army all used Ariel W/NG 350s.
Post War
After the war over 800 W/NG motorcycles were supplied to the Danish Army between 1946 and 1947. The remaining W/NGs that survived were mostly converted back into civilian specification for resale by dealers, so good examples of the military model are now rare.

2. Armstrong MT500

The Armstrong MT500 is a British military motorcycle made by Armstrong-CCM Motorcycles in Bolton, Greater Manchester, who acquired the rights to the Rotax engine enduro motorcycle SWM XN Tornado from the Italian owners and developed the MT500 for use by the British Army in the Falklands war. Electric start models were built for the Canadian and Jordanian armed forces.
In 1987, the design and production rights were sold to Harley-Davidson, who in 1993 released the MT350E. It is used by Canada, Jordan and the United Kingdom.
3. BMW R75
The BMW R75 is a World War II-era motorcycle and sidecar combination produced by the German company BMW. In the 1930s BMW were producing a number of popular and highly effective motorcycles. In 1938 development of the R75 started in response to a request from the German Army.

Preproduction models of the R75 were powered by a 750 cc side valve engine, which was based on the R71 engine. However it was quickly found necessary to design an all new OHV 750 cc engine for the R75 unit. This OHV engine later proved to be the basis for subsequent post-war twin BMW engines like the R51/3, R67 and R68.
The third side-car wheel was driven with an axle connected to the rear wheel of the motorcycle. These were fitted with a locking differential and selectable road and off-road gear ratios through which all four and reverse gears worked. This made the R75 highly manoeuvrable and capable of negotiating most surfaces. A few other motorcycle manufactures, like FN and Norton, provided an optional drive to sidecars.
The BMW R75 and its rival the Zündapp KS 750 were both widely used by the Wehrmacht in Russia and North Africa, though after a period of evaluation it became clear that the Zündapp was the superior machine. In August 1942 Zündapp and BMW, on the urging of the Army, agreed upon standardization of parts for both machines, with a view of eventually creating a Zündapp-BMW hybrid (designated the BW 43), in which a BMW 286/1 side-car would be grafted onto a Zündapp KS 750 motorcycle. They also agreed that the manufacture of the R75 would cease once production reached 20,200 units, and after that point BMW and Zündapp would only produce the Zündapp-BMW machine, manufacturing 20,000 each year.
Since the target of 20,200 BMW R75's was not reached, it remained in production until the Eisenach factory was so badly damaged by Allied bombing that production ceased in 1944. A further 98 units were assembled by the Soviets in 1946 as reparations. However the standardisation programme meant that machines that were produced by BMW and Zündapp used 70% of the same components. This simplifies the supply of spare parts for these vehicles, many of which are still in the hands of historic motorcycle enthusiasts. These vehicles are still highly desirable as collector's items because of their complex and durable technology, and are correspondingly expensive. A well-restored R75 can be still used for everyday purposes, on or off-road without problems.
In 1954 a small number of modified R75 models were produced at Eisenach (then in Soviet-controlled East Germany) for testing under the designation AWO 700, but were not put into full production. The success and reliability of the shaft-driven R75 during the war led to the US Army requesting that Harley-Davidson produce a similar shaft-driven cycle for American troops. This led to Harley producing their first ever shaft-driven model, the Harley-Davidson XA, which was a near duplicate of the R75.

Manufacturer	Production	Class	Engine	Bore / stroke	Power	Weight
BMW	1941–1946	Motorcycle/sidecar combination	745 cc flat-twin (OHV)	78 mm × 78 mm (3.1 in × 3.1 in)	26 hp (19 kW)	420 kg (930 lb) (dry)

4. BSA M20
The BSA M20 was a British motorcycle made by Birmingham Small Arms Company (BSA) at their factory in Small Heath, Birmingham. Although initially viewed as a near failure by the War Office in 1936, the M20 evolved into one of the longest serving motorcycles in the history of British military motorcycling, as well as becoming the most numerous type produced for World War II with 126,000 in active service. Many are still in use around the world today.

Development
At the outbreak of World War II BSA were Britain's largest motorcycle manufacturer with a long history of armaments supply to the armed forces. Designed by Val Page the BSA M20 started development in 1937 as a heavy-framed sidecar model with a simple 500 cc single cylinder side valve engine. It had low compression and plenty of low-end torque through a standard BSA gearbox.
Early K-M20 models from 1939 were made from standard civilian parts with the addition of military fittings, such as a large 8-inch Lucas DUl42 headlight (fitted with a black out mask), a timing-gear cover with a screw-in plug for access to the magneto drive-pinion nut and special filler caps for the petrol and oil tanks. These early military M20 models were also fitted with a long spiked prop stand on the rear nearside pivoted from a lug brazed on to the rear frame tube. Factory ledgers show that BSA exported K-M20 models to Sweden, South Africa and India, as well as civilian dealers and distributors.
M20 factory bombing
BSA workers employed making the M20 were killed in an air raid on the BSA factory in Armoury Road, Small Heath, Birmingham on the night of Tuesday the 19th of November, 1940. The factory was one of the main targets for the Luftwaffe and at 9.25pm a low flying aircraft dropped two bombs which destroyed the southern end of the BSA building in Armoury Road. Rescuers included BSA's own fire brigade who pumped the Birmingham and Warwick canal dry putting out the fire. As well as 53 workers killed, 89 were injured and it was six weeks before the last of the bodies could be recovered. Much of the factory and equipment was destroyed or damaged but BSA had 67 factories so work was transferred elsewhere and production of the BSA M20 continued.
Modifications
From October 1939 the K-M20 was designated the W-M20 and modified to include girder-forks and removal of the valanced rear mudguard. During late 1940 some civil specification M20s were purchased by the War Office which were civil models with a military paint scheme. In 1941 front and rear number plates were removed and between 1941 and 1942 active service use in North Africa showed the need for easy adjustment of the fork dampers. Special damper knobs were made of bakelite (later replaced with pressed steel).
The DU142 headlight was replaced with a smaller 6 in Lucas DU42, with a hooded, slotted black-out shield, and a universal L-WD-MCT1A tail light was fitted.
From 1942 there was a shortage of rubber so handlebar grips and foot pegs were replaced by canvas covered metal items and production was standardised, with only minor modifications until the end of World War II. By early 1942 a new large rear carrier was fitted to hold universal WD steel pannier-frames and bags. This meant repositioning the long prop stand to forward of the nearside rear wheel spindle nut. In 1943 further modifications were made include redesign of the crankcase sump shield and fitting of the Vokes high capacity air cleaner, which was a box shaped canister on top of the fuel tank and was intended to assist operations in dusty environments. In early 1945 a push-button switch was introduced for the headlight and the main lighting switch relocated to a bracket beneath the offside of the saddle.
Military service
The M20 failed on its first submission to the War Office in 1936 due to 'unacceptable engine wear'. The prototype machine required a replacement piston and cylinder after approximately 6,000 miles. In 1937 three more M20s were submitted to the War Office for testing. Two of these machines only just passed the 10,000 mile suitability tests at Military Vehicles and Engineering Establishment, MVEE, Chertsey, while a third machine was used in service trials.
In 1938 when a small batch was commissioned.Criticised for being heavy and slow, with poor ground clearance it was saved by its reliability and ease of maintenance.As the need for transport quickly gained pace orders were placed for larger quantities. Most BSA M20 motorcycles were used by the British Army but the Royal Navy and the Royal Air Force also commissioned M20's from BSA. Designed as a general-purpose motorcycle for convoy escort and dispatch use, the M20 saw action in almost every theatre of war. After the war the BSA M20 model continued in military service throughout the national service of the 1950s and in smaller numbers until the end of the 1960s, partly due to the low cost and easy availability of spare parts but also as a result of six years of harsh conditions with no serious failures.

Manufacturer	Production	Engine	Power	Transmission	Fuel capacity
Birmingham Small Arms Company	1937–1955	496cc single cylinder side valve 4 stroke	13bhp @4,200 rpm	4 Speed / chain	3 gallons

5. Can-Am Motorcycles
Can-Am is a motorcycle producing subsidiary of the Bombardier Recreational Products, a Canadian corporation. In 1973, under the direction and leadership of an American Engineer named Gary Robinson and former motocross World Champion, Jeff Smith working with a team of California desert racers, Can-Am began producing motocross and enduro bikes using engines provided by the Austrian Rotax company, another Bombardier subsidiary. The machines made an immediate impact with riders winning Gold, Silver and Bronze medals at the International Six Days Trial, a form of off-road motorcycle Olympics. The following year, the company swept the 1974 AMA 250 cc motocross national championship with Can-Am riders Gary Jones, Marty Tripes and Jimmy Ellis, finishing first, second and third. Can-Am rider Skip Olson finished second to Dick Burleson in the 1976 AMA Enduro national championship. The bikes gained a reputation for their high power outputs.
The Rotax motors used a slightly unusual style of intake. A rotary disc system was employed and this plate was altered repeatedly between T'n'T (track and trail) and MX models. This plate is accredited with the horsepower gain over conventional piston port motors used on Japanese motorcycles. The MX3, produced in 1977, was the pinnacle of Can Am. Its 36 horsepower (27 kW) was 6 more than the closest competitor.
However, soon after the Can-Am introduction, the Bombardier corporation shifted its priority from recreational products towards diversification into the transit equipment industry and then, several years later, into aircraft manufacturing. As a result, investments in the young Can-Am division were reduced substantially. In 1983, Bombardier licensed the brand and outsourced development and production of the Can-Am motorcycles to Armstrong-CCM Motorcycles of Lancashire, England. 1987 was the final year Can-Am motorcycles were produced. In 2006, Bombardier Recreational Products reintroduced the Can-Am brand with its all-terrain vehicles (ATV). In 2007, the Can-Am brand was also used to introduce the Can-Am Spyder a new three-wheeled roadster.
6. Harley-Davidson MT350E
The MT350E is a motorcycle manufactured by Harley-Davidson.
7. Harley-Davidson WLA


8. Harley Davidson XA

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Post-War twins BSA

All BSA parallel twins were pushrod operated overhead valve machines. The A7 and A10 models were semi-unit construction until about 1953 and pre-unit construction thereafter. All A50, A65 and A70 models were unit construction.

The BSA A7 was a motorcycle made by Birmingham Small Arms Company (BSA) at their factory in Armoury Road, Small Heath, Birmingham in 1946. There were two versions of the A7, the original 495 cc (30.2 cu in) version, and an improved 497 cc (30.3 cu in) version launched in 1950. Although its name was changed to the Star Twin and later the Shooting Star the BSA A7 continued in production with minor modifications until 1961.
Development
Designed by Val Page, Herbert Parker and David Munro, the BSA A7 was the first of the BSA twin-cylinder motorcycles and was ready for launch in 1939, but the outbreak of World War II delayed the launch until September 1946 when hostilities ended. The very first A7 off the production line was flown to Paris for the first motorcycle show after the end of the war. slogan 'It's time YOU had a BSA!'.

Engine
The 495 cc (30.2 cu in) twin cylinder engine produced 26 bhp (19 kW) and was capable of 85 mph (137 km/h).
A single camshaft behind the cylinders operated the valves via long pushrods passing through a tunnel in the cast iron block. This system needed a considerable number of studs and nuts to fasten down the cylinder head and rockerboxes, many of them deeply recessed and requiring well-made box spanners or the then uncommon sockets. As with other British motorcycles of the period, this kind of set-up regularly led to oil leaks.
Most motorcycles of this period tensioned the primary chain by drawing or rotating the gearbox backwards on a hinge with threaded rods, this was known as pre-unit construction. The first A7 had a fixed gearbox, bolted to the back of the crankcase, and an internal tensioner for the duplex primary chain. This gave it the appearance of unit construction and pioneered the system later used in unit-construction engines such as the BSA C12/C15, BSA B40, Triumph 3TA and so on. However, in 1954 a re-design reverted to the older system.
The electrics (as was universal for larger British motorcycles of the period) consisted of two independent systems, the very reliable and self-contained Lucas magneto, with a dynamo generator to charge the battery and provide lights. Carburation was a single Amal remote float Type 6 until 1955 when it was upgraded to a 376 Monobloc.

BSA A7 'Star Twin'

In October 1949 BSA also launched the Bert Hopwood designed 650 cc twin cylinder BSA A10. Although resembling the A7 500 cc twin, it had a revised engine design and a new A7 soon followed, based on the A10 - in response to competition from the Triumph Tiger 100. Launched as the BSA Star Twin SS the new model had twin carburettors and increased compression ratio. It also had the latest design of cylinder head with austenitic steel inlet and exhaust valves. The uprated engine was fitted to a plunger frame and finished extra chrome. Both models were produced with an option of rigid or plunger frames until 1954 and the introduction of a pivoted fork frame. The new frame also led to a separate gearbox to replace the bolted on version.
BSA A7 'Shooting Star'

In 1954 the Star Twin was redesignated the Shooting Star with a new swinging arm frame and the engine further developed by reducing the stroke to 72.6 mm and increasing the bore to 66 mm, giving a slight increase in capacity to 497 cc.
By the end of production in 1961 the BSA Shooting Star was the culmination of the development of the BSA A7, with a deep bottle green colour scheme with light green tank, mudguards and side panels, it had an alloy cylinder head, a duplex cradle frame with swinging arm rear suspension, full-width light alloy hubs and 8-inch drum brakes. Engine compression was upgraded from 6.6:1 to 7:1 and power was up to 30 bhp (22 kW) at 5800 rpm, with a top speed of just under 90 mph (140 km/h).

BSA Golden Flash
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.

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. Early Golden Flash A10s had frames with either no rear suspension, or plungers, and had a semi-unit engine and gearbox, with the gearbox bolted to the rear of the engine 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 (40 cu in), 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.

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 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. 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.
Later transfer-style Golden Flash badge In 1957, the 40 bhp (30 kW) 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.
All Post War Twins BSA Categories:

Model	Engine	First year	Last year	Notes
A7	500 cc	1947	1962	first parallel twin
A7ST	500 cc	1949	1954
A7SS	500 cc	1954	1962
A10 Golden Flash	650 cc	1950	1962	BSA's first 650 cc parallel twin
A10 Super Flash	650 cc	1953	1954	Limited edition for homologation for production racing in the USA
A10 Road Rocket	650 cc	1954	1957
A10 Super Rocket	650 cc	1958	1963	Amal TT 'racing' carburettor and new "357" full-race camshaft
A10 Rocket Gold Star	650 cc	1962	1963	Special - tuned Super Rocket in a Gold Star frame
A50	500 cc	1962	1970	Called "Royal Star" from 1966 onwards
A50C Cyclone	500 cc	1964	1965	Also A50 cc "Cyclone Clubman" for 1965 only
A50 Wasp	500 cc	1966	1968
A65	650 cc	1962	1966	Sometimes called "Star Twin"
A65R Rocket	650 cc	1964	1965	Sports model with 9:1 compression, separate headlight, and sports mudguards
A65T Thunderbolt	650 cc	1964	1972	Single carburettor. From 1971 had oil-bearing frame
A65L Lightning / Rocket	650 cc	1964	1972	Twin carburettors. From 1971 had oil-bearing frame
A65S Spitfire	650 cc	1964	1968	High performance model produced in Mk I, Mk II, Mk III and Mk IV versions
A65 Hornet	650 cc	1966	1967	Sometimes called "Hornet Scrambler"
A65F Firebird Scrambler	650 cc	1968	1972	Twin carburettors. From 1971 had oil-bearing frame, high level exhaust pipes on left hand side
A70L Lightning	750 cc			Limited edition for homologation for production racing in the USA
Fury	350 cc	1971	1972	Prototype only (never produced)

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