Author: Jonathan Whiting

Recently I’ve become fascinated by the story of Honda’s CB500 and CB550, having recently acquired one. Read reviews and road tests of either bike and you see a statements like Motorcycle Mechanics “one of the ‘show stealers'”, or Motorcyclist magazine’s “possibly the best all-around street bike on the market.”

Yet, while the story of the CB750 is well known, Honda’s 500cc series remains largely unassuming, almost exotic, except to motorcycling enthusiasts and those that remember it from the days of their youth.

Wipe away the dust and an intriguing past emerges.

The saga of this bike starts in the 1940s. An era whilst European motorcycles were leading the world when it came to performance. British and Italian bikes like Norton and Moto Guzzi were dominating The Isle of Man TT race, the most prestigious motorcycle race in the world [1]. The two American brands of the time, Indian and Harley Davidson, meanwhile were building the now iconic big engined and slow revving steads.

Then came the seventies. Marked by the quintessential sports cars, classic sport bikes, fast-living rock stars and legendary guitar solos. While rock’n roll was moving motorcycle innovation wasn’t. Fast forward half a century to modern days and it’s hard to imagine a time when companies weren’t innovating products at a relentless speed. We’re surrounded by tech centric companies. In the pre-personal computing age however, this was far from common.

When the young company Honda emerged in 1946 with the long and official name of Honda Technical Research Institute it was clear that engineering would be its DNA. Japan has a deep-rooted history of excellence in craftsmanship. Samurai swords like the fabled Katana blades were folded up to 10 times by smith workers removing impurities and forming thousands of layers of metal bonded together. In Japan there exists a culture that looks for perfection in the harmony of the parts that make up the whole. In other words, a machine must be designed to work in harmony with itself to perform most efficiently. And founder Soichiro Honda was gripped by this and desired to engineer the perfect machine.

And a Honda 500 series motorcycle engine seems to exemplify this.

“First, there was its bloodline. If you were a racing fan of – and particularly a fan of Mike Hailwood and his screaming red-and-silver Honda GP bikes – there was a certain amount of magic in that half-litre displacement. Real GPs were 500s, and the displacement had a lean competition ring to it.”

~ Cycle World

Honda released the 500 in the early 1970s, “Injecting a massive dose of technical class and good motorcycling into a rather ordinary collection of mid­sized street bikes.” Exclaimed Cycle Magazine.

Almost as quickly as they left the factory floor in Japan the CB500s and 550s were being modified as cafe racers or gentleman’s expresses. Cycle World recorded that the, “Good looks and good handling made the 500s and 550s the darling of the cafe-racer crowd.” As if their real purpose, their calling, was competition. Fortunately, the engine was more than capable. The CB550 is easily modified to rev at 11000 plus RPM. “Several CB500 machines were entered in the Production TT races on the Isle of Man in the early 1970s.” Bill Smith road the CB500 to victory in 1973 – 8.2 seconds ahead of his rival. [1]

When the young company Honda emerged, the Isle of Man was clearly on everybody’s mind. Founded by Soichiro Honda and Takeo Fujisawa in the late 40s. Honda made its first appearance at the Isle of Man in 1959. Then in 1961, just over a decade since their formation, they won the first 5 positions in each of the 125cc and 250cc categories. An unprecedented rate of success and a sign of what was to come.

Soichiro Honda was inspired by racing and passionate about engineering. Honda believed racing was the springboard to technological advancements [2]. He is cited as saying, “If Honda does not race, there is no Honda.” [3] In their formative year, Takeo Fujisawa joined Soichiro Honda, handling the companies business matters. Honda was able to spend his days in the factory and research laboratory.

With race engineering driving their designs and finding their way into production, their engines became better and more reliable [4]. Honda’s began upsetting the status quo. “They were built like a fine watch. Incredibly durable, fun to ride.” Selling his Norton for a Honda, Peter Egan, Editor-at-Large of Cycle World shared, “When I got the Honda all of a sudden I felt I could look at the map of the United States and go anywhere.”

Brooklyn Dodgers manager Walter “Smokey” Alston road a Honda. As did Steve McQueen – a man known for his riding abilities.

“[Soichiro] Honda was the kind of guy where the engine was the heart of everything,” shared Thomas Elliot, then Executive Vice President of Honda U.S.

And Honda was winning races in the Grand Prix on an inline four 500cc engine. That was until the Grand Prix brought in new rules restricting all classes to six gears and most to two cylinders (four cylinders in the case of the 350 cc and 500 cc classes), Honda joined a mass walkout and didn’t enter the Grand Prix again for the next ten years.

Clearly, however it was Honda and they had plans of one day returning.

The 500cc engine was the king of the GP. And Honda, passionate about innovating a race machine, didn’t have a 500cc inline four engine to develop in their model range.

That was until 1971 when they released the CB500 Four and shortly after the updated CB550 Four in late 73.

Yoshimura an engineer, who lead Honda back to their return to the GP in 1979, was a staunch advocate of the four-cycle approach. “Four-stroke engines,” he said, “have distinctive mechanical processes. The (intake) valve closes tight, combustion occurs, the exhaust valve opens, and the exhaust is released. It’s a sequence of independent processes, each with a different function, working together to facilitate the engine’s entire operation. This is really fascinating, from an engineering standpoint. I believe this mechanism will be the basis of further advancement in engine technology.”

Yoshimura joined Honda in 1972 and was determined, “to create something that would represent the very best in technology. We were determined to create an engine to surprise the whole world.”

The CB500, with a top speed of 115 mph [6], was already a great bike and was well received by reviewers. Cycle Magazine called it, “The thinking man’s motorcycle.” So it was unexpected when in 1973 when Honda released the upgraded 550cc engine. It was the same frame with the same classic sport styling, same tank design, similar weight, same engine case, but with a larger displacement engine.

But the surprise was appreciated.

In a June ’74 road test, Cycle World praised Honda for making the best middleweight better [7].

But engine size wasn’t the only thing upgraded. Honda’s racing and engineering fingerprints were evident on the CB550. The front forks and hub were designed for bolt on dual discs, stock. Something early adopters of the CB550 made quick use of. And there were other, less evident, improvements as well. Such as an improved clutch and uprated rear suspension [5].

Peter Watson and Graham Sanderson of Bike Magazine wrote, “We believe the CB550 provides one of the finest balances between performance, economy, and handling quality in today’s motorcycling arena. That may sound like a tribute normally reserved for two-grand plus machines, but we thoroughly enjoyed the CB550 and consider it to be one of the better bikes to emerge from Honda’s design team in recent years.”

“They embraced a kind of architectural classicism that paid tribute to both British and Italian design, with just enough Honda thrown in to reassure those who hated walking”
~ Cycle World in reference to the CB500 and CB550

It’s interesting when you consider that the CB500-550 series lasted between 1971 to 1978. Ending the year before Honda returned to the Grand Prix circuit.

The 500 series soul is its engine. Its beauty is its classicism. Its charm is its faithfulness. And its legacy is its timelessness.

Honda’s spirit was in engineering and advancing the engine. The 500cc was the pinnacle of Grand Prix racing. Perhaps, without the rigorous racing of the GP, Honda needed another way to test and develop their 500cc “heart” that would eventually see them return to the Grand Prix and their roots.

The CB 500/550 series represents the very soul of Honda.

“A machine that has earned a reputation for sporty performance, precision handling and virtually faultless reliability.”

In the dead of winter I purchased a 45 year old motorcycle. My neighbour helped me pull it out of my snow shovelled trailer. An older gentleman, he seemed surprisingly at ease as he guided it down over the harden ice. He shared how seeing the motorcycle brought him back.

But the bike looked in rough shape. It had been used in a movie shoot and they had wanted the appearance of a worn bike. I fired it up for him so he could hear the engine roar and the look in eyes said it all. “I didn’t expect that,” was all he said.

A 45 year old motorcycle, that looked like it was 45 years old, that ran beautifully at the first start of a button. That’s good engineering. Honda has left its mark.

When I first heard Honda’s CB 550 sports bike engine compared to that of the Porsches 911 sports car I was skeptical. Being a longtime admirer of the 911 this suggestion remained on my mind. And I wondered if a motorcycle and a car had anything in common. When considered from the engines of its day perhaps the analogy could make sense.

It was a well received engine. At 423 lbs dry weight it was lighter than the bigger engined sports bikes of the time and with a reduced wheelbase it was reviewed to handle well. Bike magazine reckoned there were several reasons for preferring the 500 series: ‘For starters the 500 is a lighter machine with a shorter wheelbase. It therefore has a better power-to-weight ratio than its bigger brother and, significantly, it handles better through the curves. In fact, the 500 is faster up to 60mph in a straight line and its 80mph only a fraction of a second behind the 750.’

The CB-550, unlike the model it was to replace, the CB-500, wasn’t widely exported until later models. Being first introduced to the US in 1973 and then later to Europe as the F version in 1975. Brazilian test rider Marcos Pasini wrote, that while the CB 550 Four was not officially exported to their market, the CB 550F was well received and that the CB 550 Four would have been as well by fans of the 500.

Honda published that the CB 550 featured “A new clutch. Smoother shifting. Free-valve front forks. Hydraulic front disc brakes … and we’ve increased the final reduction ratio for greater acceleration.” Upping the engine capacity by 10 percent, the CB 550 offered the same blend of performance and civility when it first arrived in the USA in late 1973. Making it the ideal base for a lightweight racer that could do the Ton, stock. The CB 500/550 remained a bit of a secret gem, preferred by cafe racers and used as “gentleman’s express” as featured in the 1975 edition of Cycle magazine.

Today people continue to enhance the performance of these bikes. And lately there’s been a revival of interest in the middleweight champion in large part because of the engine, the lower center of gravity, and yes its good looks.

A quick glance at some of the threads on the cafe builds and you will see exactly what I mean, “I think custom 550’s have the most beautiful proportions.”

“Interesting. Different. Nicely engineered. CB550 motor. Bloody brilliant.”

“That bike is sweet! My CB 500 is nice and safe in my shed and has been for years, I first customized it as a cafe racer in ’85 as a young man, maybe it’s time to give it a birthday, after seeing this awesome bike I certainly feel inspired.”

As a 1970s sports bike, the design epitomized the look and stance of the sport bikes of its day. Further the engine was shorter than the CB 750’s which meant the center of gravity was lowered – which for handling is a good thing. So the 1970s Honda CB 550 sports bike has three elements in its favour. An handsome appearance, a well engineered engine, and balanced cornering. Like the Triumphs of the 60s and the Nortons of the 50s the Honda CB 500 and CB 550 embodied the spirit of the era. Sporty performance and charming looks.

I’ve loved Porsches long before their sudden rise of popularity lead them to be the collectable they are today. To me they are the quintessential classic styling of the 60s and 70s. Beautiful, elegant, and minimalistic.

Much like, in fact, the minimally styled Japanese and European sports bikes of the 60s and 70s.

Subtle cues such as the shape of their windows, the proportion of the rear spoiler, and the round lights work together to enhance the overall design. Porsche seemed to get the balance of chrome with the 911 just right as well, using it to guide the eye along edges and curves. It’s something you see too with the CB 550. It’s a very well considered design. And both the Porsche and CB550 have a community of builders dedicated to either customizing or restoring them. Singer and Magnus Walker come to mind.

The Porsche has an incredible racing heritage. Something Honda motorcycling shares. And like Porsche, private teams raced CB 550s and people continue to modify and race them in today’s vintage editions.

Until 1998, the 911 was an air-cooled sports car, modified by private teams for racing and rallying. Then by the mid 1970s it really came into its own. Winning the Targa Florio, 24 Hours of Daytona and then the 24 Hours of Le Mans in 1979. But what really sets the 911 apart is the classic styling, beautiful silhouette, and the marmite-like polarizing love/hate relationship by car enthusiasts.

The 911 was developed as a larger more powerful replacement of the Porsche 356.

Porsche, like Honda, developed both racing and production models of their vehicles. And the 911, like the CB550, was in their sports model range. And while Porsche become iconic for the sports cars of the 1970s, Honda became iconic for the sports bikes of the same era.

The Porsche 911 and Honda CB 550 were both considered engineering marvels of their time. When compared with a Ferrari, the 911 had a smaller engine, with a 2.0L (1,991 cc) 6 cylinder flat engine, yet Porsche decided to buck the trend with their rear engined flat 6. Yet, despite all logic the rear mounted engine would continue to win races. Similarly, while others were making 2 stroke 500cc sport bikes, Honda chose to engineer a 544cc 4 cylinder. As a result both were anomalies, both were lighter with excellent handing, both generated higher than expected power to weight ratios, and both were well suited for the race track.

Yet, where the CB 550 really stands out is the displacement to power ratio (DTP). The more power an engine can generate for its size and weight the faster it can make you go. Hence, the reason engineers try to make engines with smaller DTP ratios.

The CB 550 develops 50 horse power (HP) at 8,500 RPM. In other words, it utilizes 10.88 cc to put out 1 HP. Giving it a DTP of 10.88.

The Ferrari Dino 246 GT (1968-1974) had a 2419 cc engine putting out 193 HP. A DTP of 12.5.

And the Porsche 911?

Well, that produced a DTP of 13.7 from 1973-1989.

Surprisingly it took Porsche another 40 years before they released the 911 Carrera with a DTP of 9.96.

Honda’s CB 550 engine really was an engineering marvel. Even BMWs highly desirable R90/6 with its 898 cc engine producing 67 HP didn’t come close with its DTP ratio of 13.4.

Personally, I like the 70s sporty aesthetic of the original Honda CB 550s and 500s. There’s a certain symmetry and charm to their stature. I also understand one’s desire to modify it. The CB 550 engine offers a surprising punch and with simple weight reduction and some changes to the gearing and foot positioning can be converted into a very formidable racing machine that harkens to the days gone by.

When I catch a glimpse of a Porsche 911 passing by I find I’m drawn to it. It has an appearance that sets it apart. Comparing a motorcycle of the 70s with a car that continues in production today is a far stretch to say the least. Yet, from a merely observational perspective, the parallels are undeniable. With engineering at the heart of both machines, both replacing outgoing models, both perhaps representing the best of the engineering of their times, and both classics are immediately recognizable and iconic of their era.