The Honda CB450 is a standard motorcycle made by Honda from 1965 to 1974 with a 444 cc (27.1 cu in) 180° DOHC straight-twin engine. Producing 45 bhp (some 100 bhp/ litre), it was Honda's first "big" motorcycle, though it did not succeed in its goal of competing directly against the larger Triumphs, Nortons, and Harley-Davidsons in the North American market at the time. As a result, Honda tried again, leading to the development of the four cylinder Honda CB750 that marked a turning point for Honda and beginning of the "superbike" era of motorcycles.
21-562: The CB450 had a distinctive chrome-sided fuel tank, and shared Honda's 'family' styling found elsewhere on the S90 and CD175 . Early models were known as the 'Black Bomber', or 'Dragon', but in Canada the K1 model was marketed as the 'Hellcat'. The four-speed K0 model was updated in the K1 model produced from 1968 with a redesigned fuel tank , rubber-gaitered front forks instead of sliding metal shrouds,
42-714: A 543 cc (33 cu in) four-stroke engine, which was introduced in the Alto and Fronte models. The Subaru EF engine is a 4-stroke petrol engine which was introduced in 1984 and used in the Justy and the Sumo (the export version of the Sambar). The straight-three versions of the Ford EcoBoost engine – a turbocharged 1.0-litre petrol engine – was introduced in the 2012 Ford Focus. It uses an unbalanced flywheel to shift
63-499: A five-speed gearbox and twin speedometer and rev-counter instruments mounted above the headlamp . Later developments progressed through a series of 'K' models with various improvements and styling changes including a single front disc brake , continuing to K7 versions in some markets, until the introduction of the CB500T in 1975. The Mk.I 'Black Bomber' was first shown in UK during
84-625: A horizontally split crankcase , all features distinct from current British twins. A radical feature was the valve springing: instead of the conventional coil springs, it used ' torsion bars ' – rods of steel that twisted to provide the spring effect. When it became clear that the CB450 did not have the size and power to compete in the US market directly against Triumph, Norton, and Harley-Davidson's large-displacement models, Honda shifted its focus, starting development in early 1967 of what would eventually become
105-598: A straight-twin engine. Four-stroke straight-three engines have been used in road bikes and racing bikes by several companies. From 1985–1995, the BMW K75 was produced with a straight-three engine (based on the straight-four engine from the BMW K100). British company Triumph is particularly renowned for a transversely-mounted straight-three engine. Variants have been used in their Speed Triple , Trident , Sprint , and Tiger series. In addition Triumph makes
126-432: Is a three-cylinder piston engine where cylinders are arranged in a line along a common crankshaft. Less common than straight-four engines , straight-three engines have nonetheless been used in various motorcycles, cars and agricultural machinery. A crankshaft angle of 120 degrees is typically used by straight-three engines, since this results in an evenly spaced firing interval . Another benefit of this configuration
147-404: Is perfect primary balance and secondary balance , however an end-to-end rocking couple is induced because there is no symmetry in the piston velocities about the middle piston. A balance shaft is sometimes used to reduce the vibrations caused by the rocking couple. Other crankshaft angles have been used occasionally. The 1976–1981 Laverda Jota motorcycle used a 180 degree crankshaft, where
168-502: The Diamond Jubilee Brighton Speed Trials of September 1965, traditionally held along the seafront. The bike was newly imported and its engine was not run-in, yet in a semi-competition demonstration sprint, the CB450, ridden by Allan Robinson, MBE (a Honda staff member), achieved a standing-start kilometre time of 30.1 seconds and a terminal speed of 100 mph (160 km/h). Afterwards, the CB450
189-590: The Rocket III model, various variants of which have held the record for motorcycle with the largest engine displacement. In 2019 , the Moto2 class in the MotoGP World Championship switched to using Triumph 765 cc (46.7 cu in) triple engines. Two-stroke designs are less common in straight-three engines than four-stroke designs, however several were produced by Japanese manufacturers in
210-529: The inline four of the CB750. Hansen had displayed in his office a September 16, 1968 letter from Honda R&D crediting him with changing Mr. Honda's plans for a twin to a four cylinder. Within North American Honda, Hansen's recollection of these events became well known, that in 1967 he visited Japan and toured a Honda R&D facility, where he became intrigued because he was not allowed to enter
231-665: The N600 was somehow related to the CB750 or even the CB450 traces its origins to Hansen's anecdote. Honda Sport 90 Too Many Requests If you report this error to the Wikimedia System Administrators, please include the details below. Request from 172.68.168.226 via cp1108 cp1108, Varnish XID 248895343 Upstream caches: cp1108 int Error: 429, Too Many Requests at Thu, 28 Nov 2024 10:42:07 GMT Inline-three engine A straight-three engine (also called an inline-triple or inline-three )
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#1732790527140252-487: The facility's engine testing area for "Project 300", as the successor of the CB450 was known. Hansen said he surmised that Honda was at work attempting to adapt Honda's largest car engine, the 598 cc (36.5 cu in) twin of the Honda N600 to the new motorcycle, though at about 45 hp (34 kW), it was scarcely more powerful than the CB450. Acting on this guess, Hansen mentioned to Soichiro Honda he hoped
273-412: The inherent three-cylinder imbalance to the horizontal plane where it is more easily managed by engine mounts, and so remove the need to use balance shafts. In 2016, cylinder deactivation was added, claimed to be a world first for three-cylinder engines. The advantages of a straight-three engine for motorcycles are that it has a shorter length than an inline-four engine and produces less vibration than
294-697: The introduction of Saab's 750 cc (46 cu in) two-stroke engine, which was also used in the Saab 95 , Saab 96 and Saab Sonett until 1968 after which it was replaced by the Ford Taunus V4 engine . The Wartburg cars (manufactured in East Germany) and FSO Syrena (manufactured in Poland) also used straight-three engines. The 1967 Suzuki Fronte 360 uses a 256 cc (16 cu in) two-stroke engine. In 1980, Suzuki began production of
315-426: The late 1960s through to 1980s. The Kawasaki triple engine was produced from 1968 to 1980 and was used in various road bikes and racing bikes. Most versions were air-cooled, however several were water-cooled. Similarly, the 1972–1980 Suzuki GT series engines were used for both road bike and racing bikes, and were available in both air-cooled and water-cooled versions. An example of an agricultural application
336-413: The milestone Honda CB750 . Company President Soichiro Honda ended the successful Grand Prix racing program, announcing Honda's withdrawal from racing in 1968 because it had become a distraction from production motorcycle development. American Honda's national service manager Bob Hansen later discussed his role in the decision to switch from initial plans for an all new, but still twin-cylinder, CB450, to
357-509: The new engine would not be a twin, since twins were becoming dated, and would be uncompetitive against the likes of Triumph, who were about to release a triple . The letter in Hansen's office verified that Honda had been testing a twin and changed to a four at the American's suggestion, without ever addressing Hansen's guess that the twin came from the N600 kei car . Nonetheless, the rumor that
378-445: The outer pistons rise and fall together and inner cylinder is offset from them by 180 degrees. This results in three power strokes evenly-spaced at 180 degrees each, and then no power strokes during the final 180 degrees of crankshaft rotation. The 2020 Triumph Tiger 900 motorcycle uses a "T-Plane" crankshaft where the crankshaft throws are at 90 intervals, such that the throws for cylinders 1 and 3 are separated by 180 degrees (therefore
399-400: The three throws together forming a "T" shape when viewed from the end). Among the first cars to use a straight-three engine is the 1953–1955 DKW F91 , powered by a 900 cc (55 cu in) two-stroke engine , although this was predated by the 3 cylinder 15hp Rolls Royce produced in 1905 and a number of other cars of this era also used 3 cylinder engines. The 1956–1960 Saab 93 saw
420-492: Was able to complete only some demonstration laps on the CB450 before racing began, as it was barred from competing in the 500cc category, because the FIM had deemed that it "could not be classified as a production machine as it had two overhead camshafts"! Although the CB450's sales never matched Honda's expectations, the bike had excellent engineering for the time, including reliable electrical components, an electric starter , and
441-622: Was exhibited at a motorcycle show at the Brighton Metropole Hotel exhibition centre . In December 1965, the UK magazine Motor Cycle reported that UK sales were planned from February 1966, its price of £360 being the equivalent cost to a conventional British 650cc pushrod parallel-twin. In a further publicity event, Honda (UK) entered Mike Hailwood as one of the riders in the Motor Cycle 500 mile production race at Brands Hatch during July 1966. However, Hailwood
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