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Engine Size


1962 Norton Jubilee 250 twin 1962 NORTON JUBILEE – WHAT’S IN A NAME? The name Norton Jubilee paid homage to the 60th anniversary of Norton Motorcycle production at the time of its launch in 1958 at the Earls Court Motorcycle Show in London. It was a clear break from Norton tradition, but was built specifically …

1948 Triumph Speed Twin 1948 TRIUMPH SPEED TWIN BACKGROUND In a few short years, the 5T Speed Twin went from being one of the world’s premium performance motorcycles to be Triumph’s entry-level twin. It had been surpassed by the T100 Tiger with its higher compression and hotter cams. And soon it would be bumped down …

1964 BSA A65 NEW MODELS The 1964 BSA A65 was, of course, the third model year of the new unit construction BSA twins, the 500cc A50, and the 650cc A65, which had replaced the very successful pre-unit A7 (500) & A10 (650) in 1962. BSA was very conservative in the new machine’s configuration, as was …

1988 Norton Classic Rotary 1988 NORTON CLASSIC ROTARY BACKGROUND Norton’s air-cooled, twin-rotor Wankel motorcycle was a one-year-only run, with just 100 of them built in 1987 as 1987 and 1988 models. This makes it one of the world’s rarest production Nortons, and one of the rarest classic British motorcycles overall. It came at a time …

1973 BSA B50MX 1973 BSA B50MX BACKGROUND BSA produced one of the world’s most successful 500cc singles in the Gold Star starting in 1938 and running all the way through 1963 when production ended. The entire BSA product line was being converted from non-unit construction to unit-construction and the ancient non-unit Gold Star had to …

1951 Vincent Rapide Series B 1951 VINCENT RAPIDE BACKGROUND Vincent built its reputation on it’s robust 499cc Comet single. Prior to the war, they figured out that if they doubled it, they could create a 998cc V-twin and the series A Vincent Rapide was born. Few were built prior to World War 2, which curtailed …

1957 BSA A10 Pre-Unit 650 Twin 1957 BSA A10 BACKGROUND BSA’s A10 was the 650 version in it’s twin cylinder heavyweight line. The 500cc version was called the A7. Following Triumph‘s success with its seminal 500 Speed Twin, after the war, BSA and most of the rest of the British motorcycle industry followed with their …

1962 Norton Dominator 88 1962 Norton Dominator 88 Engine A WORK IN PROGRESS In our efforts to complete our online index, and make this the world’s greatest website about classic British motorcycles, we’re building pages as fast as we can. The first thing we add are the pictures. Then come the specifications and then the …

1955 Vincent Black Prince 1955 VINCENT BLACK PRINCE BACKGROUND By the early 1950s, Vincent the company was struggling. Founder Phil Vincent, always the innovator, the risk-taker and creative genius, had been steadily improving the Vincent line through several successive ‘series’. The Series C, 1951-1953, had failed to spark much-needed sales, so for the Series D, …

1966 BSA A65 1966 BSA A65 Spitfire Special 1966 BSA A65 SPITFIRE SPECIAL This was the hot rod version of the A65, just behind the A65 Lightning. Like the Lightning, the Spitfire had twin Amal carbs (Amal Monoblocs would be standard for 1966; Amal Concentrics didn’t arrive until 1967.) A65 MECHANICALS The unit construction 650 …

BSA Bantam History ABOVE: 1950 BSA Bantam D1 123cc. SPOILS OF WAR The birth of the BSA Bantam line did not take place in England after the war. Indeed it started out as a pre-war Germany design, the DKW RT125, and DKW was taken over by the Allies as part of the war reparations Germany …

Thunderbird 6T, 649cc 4-speed gearbox, single Amal Monobloc carburettor, rated at 34hp ex-South Australian Police motorcycle was used for general traffic duties in Adelaide. The bike belongs to a friend who is an ex-police officer now living in Adelaide. I’m working on a book for New Holland Publishers in Sydney. While I was doing research …

A WORK IN PROGRESS In our efforts to complete our online index, and make this the world’s greatest website about classic British motorcycles, we’re building pages as fast as we can. The first thing we add are the pictures. Then come the specifications and then the history. So, if you see a page that just …

ABOVE & BELOW: 1977 Triumph Bonneville T140V was essentially carried over from ’76, as would be the practice from now on. Budget constraints were choking the company and it’s products. This one is in the Polychromatic Blue and Cold White paint scheme. FOCUSING ON ONE MODEL As the 1977 model year opened, the Meriden Co-op …

SHORT MODEL YEAR The 1974 Triumph Bonneville was built in very low numbers. It was a very odd year in Triumph Bonneville history. Angry workers hearing of the impending shutdown of the Triumph Motorcycles plant at Meriden, shut it down themselves in protest, in October 1973 just as production was being switched from 1973 models …

ABOVE: The 1976 Triumph Bonneville is the first to adopt left-side shift. Note shifter coming out of primary case. SPANISH AMALS? Engine mods were few. A new muffler set were now almost cylindrical reverse-cones (very little taper) & noise reduction revisions. The twin 30mm Amal Concentric carburetors were now being produced by the company’s Spanish …

1969 Norton Commando Fastback ABOVE: 1969 Norton Commando Fastback MODEL DESIGNATIONS The 1969 Norton Commando came in one additional model for 1969, its second model year in production. The 1968 Norton Commando was available in one model only, and so was simply called ‘Norton Commando’, even though it had what was to become known as …

1954 VINCENT BLACK SHADOW-ONE OF THE LAST The Vincent Motorcycle Co. closed its doors in 1955, so this 1954-model was built one year before the end. Vincent was a low-volume producer of high-quality motorcycles, and high-priced for the time. From the end of WWII until their demise in 1955, they barely produced 11,000 bikes total, …

1950 VINCENT COMET RUNNING GEAR The Vincent Comet had frame similar in layout to the V-twin Vincent Black Shadow which included Vincent’s proprietary cantilever rear suspension and Vincent’s Girdraulic forks up front. And, like the big V-twins, the engine was a stressed member of the frame, eliminating the need for front downtubes and an engine …

1952 VINCENT BLACK SHADOW BACKGROUND Brilliantly designed by doubling up the 499cc Vincent Comet single-cylinder engine into a 50-degree V-twin, the Vincent Black Shadow was introduced in 1949. It followed on the heals of the Vincent Rapide, which was more of a touring bike. The buying public wanted more power, more “sport” and so the …

1953 VINCENT BLACK SHADOW BACKGROUND Brilliantly designed by doubling up the 499cc Vincent Comet single-cylinder engine into a 50-degree V-twin, the Vincent Black Shadow was introduced in 1949. It followed on the heals of the Vincent Rapide, which was more of a touring bike. The buying public wanted more power, more “sport” and so the …

1936 VINCENT COMET FRAME & CYCLE GEAR The Vincent Comet had frame similar in layout to the V-twin Vincent Black Shadow which included Vincent’s proprietary cantilever rear suspension and Vincent’s Girdraulic forks up front. Also typical of Vincent motorcycles, the Comet had two Single Leading-Shoe (SLS) front drum brakes, one on each side. 1936 VINCENT …

1935 VINCENT COMET RUNNING GEAR The Vincent Comet had frame similar in layout to the V-twin Vincent Black Shadow which included Vincent’s proprietary cantilever rear suspension and Vincent’s Girdraulic forks up front. Also typical of Vincent motorcycles, the Comet had two Single Leading-Shoe (SLS) front drum brakes, one on each side. COMET ENGINE DESIGN The …

1950 VINCENT BLACK SHADOW BACKGROUND Brilliantly designed by doubling up the 499cc Vincent Comet single-cylinder engine into a 50-degree V-twin, the Vincent Black Shadow was introduced in 1949. It followed on the heals of the Vincent Rapide, which was more of a touring bike. The buying public wanted more power, more “sport” and so the …

1949 VINCENT COMET RUNNING GEAR The Vincent Comet had frame similar in layout to the V-twin Vincent Black Shadow which included Vincent’s proprietary cantilever rear suspension and Vincent’s Girdraulic forks up front. And, like the big V-twins, the engine was a stressed member of the frame, eliminating the need for front downtubes and an engine …

1951 VINCENT COMET RUNNING GEAR The Vincent Comet had frame similar in layout to the V-twin Vincent Black Shadow which included Vincent’s proprietary cantilever rear suspension and Vincent’s Girdraulic forks up front. And, like the big V-twins, the engine was a stressed member of the frame, eliminating the need for front downtubes and an engine …

1960 TRIUMPH TWENTY-ONE HAS BATHTUB STYLING. The British home market had been hungry for cheap transportation after WWII, and commuter motorcycles helped fill that role. But England being…well, England, was wet and rainy and to prevent rust an owner needed to wipe his bike down each night after getting home from work. This was a …

INTRODUCING THE 1938 TRIUMPH SPEED TWIN It’s hard to overstate the significance of the introduction of this bike. Until the moment of its launch, just about every British motorcycle manufacturer was producing mostly big air cooled pushrod singles, but as displacement and performance grew, so did engine vibration. They’d reached the single’s practical limits at …

TRIUMPH DAYTONA IS HOT The Triumph Daytona is essentially the high-performance version of the T100C Trophy 500 twin. Fitted with a new alloy cylinder head mounting two Amal Monobloc carubretors ‘Bonneville-style’, it also had higher compression and hotter cams. The increased the size of the intake valves, and found that they intake and exhaust valves …

CROWDED MARKET The Norton Dominator was Norton’s entry into the crowded vertical twin market, & it was intended to capitalize on the success of, & hopefully steal some sales from, the trend-setting Triumph Speed Twin. When it was introduced in 1949, the 500cc Dominator Model 7 was a handsome enough machine. The new engine was …

1947 TRIUMPH 3T DELUXE BACKGROUND Triumph production reverted to civilian machines in 1946, following the end of World War II. The biggest market that the British motorcycle industry needed to fill was the pressing need for cheap, economical transport to-and-from-work. In response, Triumph announced the new 3T, a 350cc companion to Edward Turner’s 500cc 5T …

1959 TRIUMPH TWENTY-ONE HAS BATHTUB STYLING. The British home market had been hungry for cheap transportation after WWII, and commuter motorcycles helped fill that role. But England being…well, England, was wet and rainy and to prevent rust an owner needed to wipe his bike down each night after getting home from work. This was a …

BSA A65: THE MOVE TO UNIT CONSTRUCTION The BSA A65-A50 twins, the A65 being a 650 twin & it’s smaller sister-bike the BSA A10 500 twin, were the natural result of the trend, then sweeping the British motorcycle industry, to unitize engine construction. Prior, most engine packages were made up of separate crankcase, primary case …

1946 TRIUMPH 3T BACKGROUND As Triumph production reverted to civilian machines immediately after the end of World War II, the company announced the new 3T, a 350cc companion to Edward Turner’s 500cc 5T Speed Twin. The 3T was similar in many respects to the Speed Twin, but also borrowed features from the TRW and 3TW …

Les Harris Bonnevilles Rise from the Ashes The story of the Les Harris Bonnevilles is one of the more fascinating in all of Classic British Motorcycles lore. Such was the reputation of the Triumph name & the enthusiasm & optimism of its most devoted followers that after the 1983 collapse of the Meriden Co-operative-owned Triumph …

EVOLUTION OF THE ATLAS The Norton Atlas evolved from the Norton Dominator line, which had grown since its inception in 1949 from 500 cc to 600cc then again to 650cc with the fire-breathing twin-carb Dominator 650SS. The Norton Atlas was the next logical step. The venerable Bert Hopwood-designed vertical twin that had started out life …

1961 TRIUMPH TWENTY ONE HAS BATHTUB STYLING. The British home market had been hungry for cheap transportation after WWII, and commuter motorcycles helped fill that role. But England being…well, England, was wet and rainy and to prevent rust an owner needed to wipe his bike down each night after getting home from work. This was …

ARIEL RED HUNTER BACKGROUND The 1930s were indeed the Golden Age for the British motorcycle industry. At the time, nearly all of them relied heavily on one basic engine architecture: the air-cooled, pushrod OHV single, and most marques had built their lineup of 350 and 500 singles. As the 1930s opened, Ariel’s product line was …

1964 AJS MODEL 16 BACKGROUND Parent-company AMC secured some lucrative contracts from the British government to build, among other things 80,000 Matchless G3s and G3/Ls. After the war, these became the basis for their civilian middleweight line. As always, every Matchless motorcycle had a near-identical twin in the AJS lineup. This was the AJS Model …

VINCENT RAPIDE BACKGROUND Vincent head engineer Phil Irving was working on some tracings of the firm’s 499cc single cylinder engine in 1936. As things got moved around, two of the tracings lined up roughly in the shape of a V-twin. With a little cajoling, he quickly lined it up enough to see that it would …