By late 1970s, there was a power war raging between Japanese motorcycle manufacturers and Honda was determined to win it

Honda has never been afraid to push the envelope in its motorcycle engineering, either in road bikes or racing machinery. In the 1960s, the prevailing thinking suggested that for more power, more cylinders were needed and Honda’s racing motorcycles were incredibly complex - and successful. In the 1970s, Honda introduced the four-cylinder CB750, in competition with the ancient parallel twin designs of the British manufacturers. But, towards the end of the decade, thoughts turned once again to even more cylinders.

When Honda arrived on the racing scene in the early 1960s, it did so with some incredible engineering. They weren’t the first manufacturer to design an inline four-cylinder engine - that accolade goes to MV Agusta and Gilera - but, in the smaller displacement classes, their innovation was startling: twin-cylinder 50cc, four-cylinder 250 and 350cc and six-cylinder 250cc.

The Honda road bikes were slightly more conventional, although their 350cc parallel-twin engine gave performance equalling that of 650cc British engines.

The CB750 of 1969 really set the cat amongst the pigeons and pointed the way forward for those who were prepared to look without rose-tinted spectacles. That bike and its engine set a template that is still in use today and set the Japanese industry on a course to world domination, sweeping all before it.

Soichiro Honda, the founder of the company, realized that to stand still was to be in danger of being overtaken in the fast-developing world of Japanese motorcycles. The CB750 had been a huge success but a new flagship sport bike was needed, which had to be faster and more powerful than the CB750. Honda decided that four cylinders would not be enough so made the decision that the new bike would have six cylinders. Thanks to their racing experience, this wasn’t as mad an idea as you might think.

Shoichiro Irimajiri, the designer of the CBX, revealed that a four-cylinder 1000cc engine was initially considered, especially when a test engine proved to be light, powerful, and much faster than the six-cylinder engine already being tested.

But Honda, stung by criticism from Yamaha that its products were staid and boring and that Honda was spending more time on developing its car range, decided the best reply would be in the form of a six-cylinder engine.

Irimajiri: “…we felt there was something exhilarating and exciting about the 6-cylinder CBX that was lacking in the 4-cylinder CB1000F... something in the CBX that could not be measured in numbers like speed and weight, (something that) made it a very sexy machine.”

Whereas the racing six-cylinder had a displacement of 250cc, the CBX was designed with a 1000cc displacement, or four times the size. This brought its own set of problems, all of which had to be addressed.

The first was of size: six cylinders in a line make for a very wide engine and a long, whippy crankshaft so drive to both the gearbox and camshafts was taken from the center of the engine, between cylinders 3 and 4. Similarly, the alternator was not affixed to the end of the crankshaft, as on the CB750’s engine.

The other problem was weight and this was addressed by extensive use of aluminum and magnesium. The engine was used as a stressed member, eliminating the need for lower frame tubes. Despite all this, the CBX1000 still weighed in at a slightly porky 550 pounds.

Amazingly, it was tiny Italian manufacturer Benelli that released the first six-cylinder engined bike in 1972, the Sei 750 (which was actually based on the Honda CB500 Four engine). This bike, brilliant as it was, was never going to be able to challenge the might of Honda, with all the resources and dealer network at its disposal. Despite the Benelli looking positively lean and lithe next to the Honda, everyone knew which one would sell better.

In an example of ‘anything you can do, I can do better,’ Kawasaki took only a year to come up with a response to the CBX. In 1979, the Z1300 was launched, also a six-cylinder but this time liquid-cooled and featuring a shaft final drive.

When it was launched in 1978, it wasn’t the immediate sales success Honda was hoping for. Both customers and insurance companies considered it far too complex. Of course, these fears were unfounded: Honda's build quality meant that, even with six cylinders, two camshafts, 24 valves, and six carburetors, it was as reliable as any of its four-cylinder bikes.

But it was expensive and Honda had a viable alternative in the CB900F which, with its four-cylinder engine, wasn’t all that much slower, even if it did lack the appeal of a six-cylinder engine.

In four years of production, Honda built 38,079 CBX1000s in Japan and a further 3,150 in its US factory.

Yes, the six-cylinder engine is an imposing lump that looks impossibly wide, but in actual fact, it doesn’t hamper ground clearance too much when cornering.

Journalist L.J.K. Setright wrote of the CBX's width: "Don't tell me that its engine is too wide: It is no wider than the legs of a rider, so it adds nothing to the frontal area, and personally I would rather have my legs shielded by a cylinder apiece than exposed to every blow ..."

In 1981, Honda decided to increase the appeal of the CBX by offering a faired version, called the CBX1000B, creating a sports tourer.

Interestingly, around the same time, they also did the same to the Gold Wing, which was initially a naked bike, and, in the process, created rivals for their own products, which seems a bit counter-productive. Given that the Gold Wing is still with us, we know which bike won that particular battle.

However, it’s not a totally fair comparison as the Gold Wing was much larger and heavier while the CBX was a sports bike, even with its fairing and panniers.

When the magazines got their hands on the CBX1000, the response was extremely positive.

In the February 1978 issue of Cycle Magazine, editor Cok Neilson wrote this of a review of a pre-production bike, after a four-day review at Orange County Raceway and Willow Springs Raceway and on a dynamometer. "The objective - to build the fastest production motorcycle for sale anywhere in the world - has been met,” he wrote. Comparing the CBX to the CB900F, Setright added,"The CBX feels better and goes better, and the difference is greater than the difference in price, so the costlier bike is actually the better bargain. ... The CBX engine is as responsive as a racer, the nicest cycle motor to ever reach the street.”.

Cycle World magazine achieved a quarter mile time of 11.64 seconds at 117.95mph. The CBX was also the first motorcycle they had tested that achieved 130mph top speed.

In 1981, the CBX was slightly detuned - from 105 to 100 horsepower - and so later models aren’t quite fast as the ’78, ’79, and ’80 models.

Whichever way you look at it, the CBX1000 was a ground-breaking model, one whose influence is still being felt in motorcycling today, most obviously in the six-cylinder BMW K1600 models.

It depends very much on condition, of course, but a fully restored CBX can fetch in excess of $20,000.

Cycle World magazine achieved a quarter mile time of 11.64 seconds at 117.95mph. The CBX was also the first motorcycle they had tested that achieved 130mph top speed.

CBX1000s were built in both Japan and America

Honda built a 250cc six-cylinder racing bike in 1966 but it was Benelli who launched the first production six-cylinder motorcycle in 1972.

It depends very much on condition, of course, but a fully restored CBX can fetch in excess of $20,000.

Cycle World magazine achieved a quarter mile time of 11.64 seconds at 117.95mph. The CBX was also the first motorcycle they had tested that achieved 130mph top speed.

CBX1000s were built in both Japan and America

Honda built a 250cc six-cylinder racing bike in 1966 but it was Benelli who launched the first production six-cylinder motorcycle in 1972.

Harry has been writing and talking about motorcycles for 15 years, although he's been riding them for 45 years! After a long career in music, he turned his hand to writing and television work, concentrating on his passion for all things petrol-powered. Harry has written for all major publications in South Africa, both print and digital and produced and presented his own TV show called, imaginatively, The Bike Show, for seven years. He held the position of editor of South Africa's largest circulation motorcycling magazine before devoting his time to freelance writing on motoring and motorcycling. Born and raised in England, he has lived in South Africa with his family since 2002. Harry has owned examples of Triumph, Norton, BSA, MV Agusta, Honda, BMW, Ducati, Harley Davidson, Kawasaki and Moto Morini motorcycles. He regrets selling all of them.