Blew Away the Competition

Every motorcycle manufacturer has its fans, but those who appreciate true innovations in bikes speak fondly and with reverence of a machine that established a worldwide reputation: the vintage Honda CB450 K0 Black Bomber.

Until the CB450 was unveiled in 1965, many manufacturers dismissed Japanese motorcycles as nothing more than economical little motorbikes with a reputation for dependability. No one considered Honda cycles to be on the same track with powerful performance machines. The common belief was that to be a performance bike, a motorcycle had to displace at least 500cc, and Japan's motorcycle makers had nothing like that.

Automotive writers began to hear reports in 1964 that Honda was experimenting with a bike to challenge the supremacy of various twin-camshaft motorcycles, particularly those made by British maker Triumph. When Honda began allowing journalists to test their experimental models, the automotive writers found the new design quick – over 100 miles per hour – but with stiff handling and a need for high revs to reach performance level.

Initially the executives at British motorcycle companies, home of the traditional twins, underestimated Honda's developments. For instance, Triumph's CEO at the time, Edward Turner was convinced that the Japanese were far away from constructing the kind of big, husky sporting twins that U.S. bikers wanted from British makers. Turner also lulled his American distributors into the mistaken comfort of this viewpoint.

Meanwhile, Honda appeared to be following the teachings of the Chinese soldier-sage, Sun Tzu, author of the classic "The Art of War." Honda built up its retail outlets in the United States, while maintaining an innocent front that kept its competitors from becoming alarmed.

Then in 1964, a journalist visiting Honda's factory track in Suzuka, Japan, found out that the manufacturer was actually testing a 450cc twin. British manufacturers were thunderstruck.

When it went on sale a year later, the vintage Honda CB450 K0, nicknamed the Black Bomber, blew away its motorcycle competition. By investing in the best tooling then available and a state-of-the art foundry, Honda had proven it could build new motorcycle designs that were beyond the capabilities of other manufacturers still using old equipment.

The technical specs on the Black Bomber showed the kind of engineering feats that make gear heads go glassy-eyed: double-overhead camshafts, a crankshaft supported by four caged roller bearings and a primary drive operated by spur gears. Torsion bar springs – tubular guides made of short lengths of splined steel – seated the valves. The Bomber also came with a first on a mass-production motorcycle: a pair of 36mm constant-velocity carburetors. Although Honda claimed its short-stroke engine could make 112 mph, the Black Bomber's top recorded speed was 102 mph, noted by Cycle World magazine in an August 1965 review. However, Honda’s 450 was at its most powerful at more than 6,000 rpm, an unheard-of feat among the cycles of its day.

Honda realized later that the vintage CB40 K0 could have been even more successful with a more mainstream body style and a 5-speed transmission, both of which came along later. The Black Bomber also suffered from poor rear shocks, vibration and the need for a long warm-up. Honda addressed this issues when it introduce the K1 in February 1968. By later that same year, the CB 450 K0 had been surpassed as Honda's flagship, although it remained in production as a middleweight bike until 1974.

Flawed though it may have been, the vintage Honda CB450 K0 blazed a trail that gave its manufacturer a direct route to the top ranks of worldwide motorcycle makers.