When Honda revealed its CB750 Four motorcycle to American dealers at a January 1969 sales meeting, no one – not even Soichiro Honda himself, in attendance – could have predicted the impact a single model would have on the entire industry worldwide. Often described as the first superbike, and perhaps even the first “Universal Japanese Motorcycle,” Honda’s game-changing CB750 Four marks its 50th birthday in 2019.
To be clear, the CB750 wasn’t the first four-cylinder motorcycle, and it wasn’t even the first to arrange these cylinders inline, mounted transversely across the frame. Its single overhead camshaft design wasn’t cutting-edge, either, particularly since its CB450 model had offered American buyers double overhead camshafts since 1965. It was the first motorcycle from a mainstream manufacturer to come with electric starting and disc brakes, and, overall, the CB750’s blend of performance, versatility and convenience was unmatched by anyone else in the industry, especially at a price of $1,495.
Early models with sand-cast crankcases are the most collectible. This 1969 Honda CB750 Four sold for $27,500 at Mecum’s Las Vegas sale in January 2019. Photo courtesy Mecum Auctions.
Honda had done well with its small-displacement motorcycles in the American market, but realized it lacked a high-performance model to compete with rival British and American brands. The technically sophisticated CB450 was meant to address this market, and development engineer Yoshiro Harada was quick to point out that Honda’s 450cc twin was better, performance-wise, than 650cc motorcycles from Norton and Triumph. Such logic may have worked in Japan, where the market for large and powerful motorcycles was miniscule, but to American riders, there was no replacement for displacement.
Photo courtesy Mecum Auctions.
At the time development began on the CB750 Four, no Japanese motorcycle manufacturer built a bike larger than 650cc. When pressed for specifics by Japan on what size engine American buyers wanted, American Honda couldn’t even give a specific answer, saying only, “the bigger the better.” Harada, tasked with establishing the requirements for this new big-bore bike, learned that Triumph was about to debut a 750cc high-performance model, so this became the displacement target. As for output, Harada knew that Harley-Davidson’s new Shovelhead V-twin made 66 hp, so 67 hp became his benchmark for the Honda.
Photo courtesy Mecum Auctions.
In February 1968, Honda assembled a team of around 20 employees to begin working on the design of the CB750 Four. The engine would be a four-cylinder, exhaling though four exhaust pipes, two on each side. Instead of featuring a performance-themed, café racer riding position, the Honda adopted an upright riding position favored by American buyers, improving comfort and adding to its appeal on these shores. Other design goals required the bike to be stable at prolonged speeds as high as 100 mph, yet maneuverable in traffic; employ brakes that were reliable and resistant to fade even after repeated high-speed stops; produce minimal vibration and noise to reduce rider fatigue; employ controls that were ergonomic and easy to learn; reduce the amount of required maintenance and servicing; and finally, utilize original designs that could easily be mass-produced.
Electric start was standard on the CB750, but Honda included a kick starter as well. Photo courtesy Mecum Auctions.
Reliability was paramount as well. As Craig Fitzgerald wrote in a June 2006 Hemmings Motor News article, the CB750 engine was run at 6,000 rpm for 200 hours before being certified for production. As if that wasn’t enough, the engine was then spun up to redline, 8,500 rpm, for 20 hours of testing. The finished product was so smooth that – with all four carburetors properly synchronized – one could reportedly stand a nickel on edge on the engine casing, yet the bike could still run the quarter-mile in roughly 12 seconds and attain a top speed around 120 mph.
Even as the CB750 Four was being announced to U.S, dealers, Honda in Japan was speculating over what demand would be for its new model. Initially, forecasts predicted sales of 1,500 units per year, but when word of the bike’s capabilities and price point (roughly 2/3 that of high-performance models from England, and less than half that of certain European models) got out, demand skyrocketed. The forecast quickly grew to 1,500 units per month, then doubled to 3,000 units per month, still not quite enough to meet demand.
The engines for the CB750 Four were initially built at Honda’s Saitama Factory, which had previously assembled Honda power equipment. Unsure its new model would prove successful, Honda was initially unwilling to invest in the expensive molds needed for die-casting, and instead used sand-molding to create the crankcases of early production examples. When the forecasts swelled from 25 engines per day to 100 engines per day, line workers simply could not keep up; in response, Honda upgraded the production facility for die casting and hired additional employees to staff the line. By 1971, two years after the CB750’s debut, even this wasn’t enough to meet demand, and production of engines (and frames) was transferred to the company’s Suzuka factory.
Today, the most valuable Honda CB750 Fours are the Saitama-built models with sandcast crankcases, denoting the earliest production. More valuable still are prototypes, of which four were assembled and two are known to survive. In March 2018, one of these prototypes, finished in Candy Gold, sold for £161,000 (then, roughly $223,550), becoming the most expensive Japanese motorcycle ever sold at auction. Four years earlier, the Candy Blue prototype sold at auction for $148,100, making it – at the time – the second-most expensive Japanese bike to cross the block. Of the remaining prototypes, the Candy Red example was sent to the crusher, while the Candy Green CB750 Four was last seen in France; today, its whereabouts remain a mystery.
The 1991 Honda CB750 Nighthawk. Photo courtesy of Honda America.
The original CB750 Four didn’t remain atop the performance ladder for long, but the model’s blend of value and versatility made it the motorcycle of choice for generations of riders. Perhaps the best measure of the model’s success is its longevity: Though updated with some regularity, variations of the 750cc, air-cooled, four-carburetor, inline-four standard remained in Honda’s product line though 2003, when the last CB750 Nighthawk rolled off the assembly line.