The first forgotten super motorcycle-BSA "Rocket Three Cylinder"

Before the 1970s, the motorcycle brands that riders talked about were not Honda, Suzuki, Kawasaki and Yamaha, but heavy motorcycles of European brands and cruise motorcycles of North American brands. Take Britain as an example. At that time, there were at least three manufacturers: Triumph, Norton and BSA.

As early as11970s, British BSA company had produced Otto electric two-wheelers and began to produce and sell bicycles in 1980s. 1903 introduced an experimental motorcycle with an engine displacement of 233mL, 1909 produced and sold motorcycles. After the outbreak of World War I, BSA company provided a large number of military motorcycles, cars and folding bicycles for the British military, so it has been greatly developed. During World War II, BSA continued to produce motorcycles and provided about126,000 M20 motorcycles to the military.

After the war, thanks to the urgent demand for transportation and other production and living materials, BSA's business is booming. 195 1 year, BSA successfully merged with another old motorcycle manufacturer in Britain, and also acquired companies such as Sunshine and New Hudson, becoming the largest motorcycle manufacturer in the world at that time. However, at this time, the crisis and hidden dangers have been buried, and the emerging Japanese motorcycle manufacturers and European tycoons began to shake the boss position of BSA. 1960, BSA Group, which was in financial crisis, was forced to sell Daimler to Jaguar and the bicycle department to Raleigh. 1972, rich manganese copper group acquired BSA, and planned to reorganize BSA, Norton and Kaixuan into a new group. Unfortunately, this effort failed, and BSA, Norton and Triumph closed down one after another.

Among the many models produced by BSA, Rocket 3, which was introduced in 1960s and 1970s, is considered as an unavoidable classic model. This model "two flowers, one for each table" is sold by BSA and Triumph under the names of "Rocket Three Tanks" and "Trident" respectively. Although this model came out in the late 1960s, the platform of this model was built a long time ago, namely, 1937 Edward Turner's "Fast Twin Cylinder" and the next year's "Tiger" sports version. For this reason, riders who know the inside story like to call "Rocket Three Cylinder" a "Half Tiger".

At that time, in order to enhance the market competitiveness, BSA and Kaixuan decided to launch a parallel three-cylinder motorcycle with stronger performance on the basis of the existing parallel two-cylinder engine platform. Their 650mL displacement parallel two-cylinder engine uses 360 crankshaft, while the newly developed parallel three-cylinder engine uses120 crankshaft, so it runs smoothly. Although most British motorcycles are equipped with wet clutches, this parallel three-cylinder engine is different. It introduces a single-chip dry clutch between the main chain box and the gearbox.

1965 The earliest prototype of "Rocket Three Cylinder" came out and was ready to be put into production in 1967. However, due to the separate production and sales of BSA and Kaixuan brand, the manufacturer sought Og design studio to optimize the design, resulting in a delay of 18 months. The new model is no longer as traditional as the old British motorcycle, and uses a more square fuel tank instead of water droplets. 1968, this parallel three-cylinder engine model was finally put into production. All engines are produced in the Little Heath Factory of BSA, but the Trident Trident is assembled in the Meriden Factory of Coventry, and the three cylinders of BSA rocket continue to be assembled in the Little Heath Factory. The main difference between the two is the engine and the frame-the "Rocket Three Cylinder" adopts the double-tube cradle frame of BSA A65 model, so the parallel three-cylinder engine is installed in the frame slightly in front, thus distributing more mass to the front wheels; Trident adopts a single-tube frame of Triumph bonneville model, and the cylinders are installed vertically. As for the other differences, it is mainly the difference of spraying style and detail setting.

"Rocket three-cylinder" air-cooled parallel three-cylinder engine, cylinder diameter, stroke 68mm × 70mm, displacement 740mL. Different from the cylinder head of Honda CB750, the "Rocket Three Cylinder" adopts overhead valve mechanism; The exhaust pipe of the middle cylinder adopts bifurcated design, which is collected into the exhaust pipes of the left cylinder and the right cylinder respectively. This power heart can output the maximum power of 43kW at the speed of 7500rpm. With the support of the 4-speed transmission system, the "three-cylinder rocket" with a curb weight of 226kg can be driven to fly quickly, and the top speed can exceed188km/h. In that year, the "three-cylinder rocket" set a new speed record at Daytona Motorcycle Festival in California, USA, and it was not until 197 1 that it was adopted by Kawasaki Z/. On the actual measurement organized by Cycle World in 1968, the top speed of "Rocket Three Cylinder" was 188.34 km/h, and it took 5.7s to accelerate from standstill to 100km/h, and it took13.50000.0000000000001

This parallel three-cylinder engine has great potential and even won the favor of many professional racers. For example, Doug Haley invited Rob North, an expert in frame design, to optimize the frame structure and launch Formula 750 racing car. In the Daytona 200 competition of 197 1, this parallel three-cylinder engine from Britain shines brilliantly, dominating the top three: Dickerman and Don Emurd, who are driving the BSA "rocket three-cylinder", respectively, and Jean Romero, who is driving the trident, is the runner-up. John Cooper, on the other hand, drove a "three-cylinder rocket" to compete for the GP500, and defeated Agostini driving Augusta at Mallory Park Circuit in 197 1 season!

With excellent engine performance and stable frame, this side-by-side three-cylinder engine enjoys a high reputation on the track and market, and has won the support of many riders. From 1968 to 1975, a total of 27,480 vehicles were produced by BSA "Rocket Three Cylinder" and Trident Trident in the seven years of formal production.

The parallel three-cylinder engine in Britain, as well as Honda CB750 and Kawasaki Mach III H 1, have pushed mass-produced motorcycles to a new height in terms of technology, handling performance and running ability, and * * * has set off a huge trend of modern super motorcycles. Although only Honda CB750 was later considered as the first modern super motorcycle, in fact, BSA "Rocket Three Cylinder" was launched one month earlier than Honda CB750.