Common Tread

50 years ago, Honda unveiled the CB750 and changed motorcycling

Oct 26, 2018

Not too long ago, a story showed up in my news feed about the 50th anniversary of the Russians’ brutal suppression of the "Prague Spring" uprising in Czechoslovakia. That put me in the mood of 1968, the most revolutionary year of the post-WWII era.

In Paris, students took to the streets in huge demonstrations against capitalism and consumerism. They eventually allied with trade unionists to bring the French economy to a near-complete halt. To this day, those 1968 demonstrations are seen as the defining moment in France’s modern history.

Meanwhile, in the United States, Martin Luther King Jr. and Robert F. Kennedy were assassinated. Opposition to the Vietnam War flowed into the political mainstream. The Democratic National Convention became a referendum on Vietnam, and for a few days Chicago resembled a war zone, too. 1968 was not a year for peaceful, incremental change.

1969 Honda CB750
1969 CB750K0. Honda photo.

The revolution came late to the motorcycle industry, but when the Honda CB750 was unveiled at the Tokyo Motor Show that November, it changed the world of motorcycles forever.

Tokyo Motor Show
The debut of the CB750 at the Tokyo Motor Show created a buzz. Honda photo.

“Victory has a hundred fathers…”

In the mythology of the CB750, many stories are told about the genesis of the model. Some people say that Soichiro Honda himself realized the company needed to make a much bigger bike when he was traveling in Europe and saw a motorcycle cop on a Triumph.

“What’s that small Triumph?” he wondered, until he realized it wasn’t the bike that was small, but the cop who was so much bigger than any Japanese test rider.

Bob Hansen
Bob Hansen, the man behind Honda's U.S. distributor service training program and Team Hansen Honda. TeamHansenHonda.com photo.
At American Honda, they like to credit Bob Hansen with the idea. I discussed the development of the CB750 with Hansen at length about 15 years ago. I felt he might’ve been aggrandizing his role, but he ran the U.S. distributor’s service training program and a quasi-official race team, and was the first "gaijin" who really had the respect of Honda’s senior management.

As that story goes, Hansen was in Japan for meetings with Mr. Honda. On a tour of the factory, Hansen was denied entry into one particular R&D area. He was told that there was a “secret motor” being developed in there. Later that day, he asked about the project over lunch with Soichiro Honda, who smiled and said they were working on “the king of motorcycles.”

Hansen knew that Honda had a 600 cc twin-cylinder auto engine, and he was worried the company planned to use that as the basis for a Bonneville-beater. But he also knew that Triumph and BSA had a 750 cc triple motor ready to go; the only reason they hadn’t commercialized it was that Triumph was already selling all the Bonnevilles it could make in the U.S. market.

Hansen told Mr. Honda, “It better not be a twin!”

“Why do you say that?” Mr. Honda asked.

Hansen had a gut feeling the British triples would soon hit the market, and made a daring suggestion, “It should be a four!”

Mr. Honda nodded and said, “We have experience making four-cylinder motors for racing.”

Hmm…

Hansen probably did influence the design, but the single person most responsible for the CB750 was a senior Honda engineer named Yoshiro Harada. Harada had designed Honda’s largest bike to date, the CB450 twin. That model was introduced in 1965. The arrival of the "Black Bomber" 450 struck fear into the British manufacturers and it hurt the British in their domestic market. However, the CB450, despite being sharply priced, didn’t sell as well stateside.

Honda brochure
Even in this brochure for the Japanese market, Honda made it clear the CB750 was built for U.S. market, calling it "Distinctly American." Honda image.

Yoshiro Harada toured the United States in 1967, hoping to inspire Honda dealers to sell more CB450s to American riders. Instead, it was the dealers who influenced Harada. They convinced him that Americans wanted torque more than horsepower and, as such, that there was no replacement for displacement. Just as important, Harada viscerally experienced the vastness of the American landscape on that extended road trip. He returned to Japan convinced that while the CB450 was plenty big enough for the Japanese domestic market and Europe, his American dealers were right.

Reinventing the motorcycle… and its development process

Harada didn’t actually get approval to develop a new four-cylinder motor until February of 1968. By then, BSA must nearly have had an assembly line for 750 cc triples up and running at its Small Heath factory. But Honda had recently made a big investment in computers, and Harada’s secret project made far greater use of computer-assisted design than ever before, which sped the process.

Honda CB750 exhaust
Four-into-four exhausts emphasized the four-cylinder engine. 1969 Honda CB750K0. James Tyler Reed photo.

The core team was small. At the beginning, only about 20 people worked on "Project 300" full-time. Harada’s design brief, however, was sweeping. He wanted:

  • A four-cylinder motor that evoked Honda’s Grand Prix racers
  • A stable, reliable cruising speed of up to 100 miles per hour
  • Brakes capable of rapid and repeated stopping from high speeds
  • Minimal vibration and noise in order to reduce rider fatigue during rides
  • Comfortable ergonomics
  • Improved standard of quality for lighting, switchgear, and all controls
  • Extended service intervals
  • And the whole thing had to be affordable to mass produce

Within six months, Harada’s team had prototyped a four-cylinder motor, which was tested in a CB450 chassis.

The test mule was fast. One of Harada’s last big decisions was how to slow it down. While most of the early prototypes had a drum brake, he felt that a disc brake was a better alternative. By that time, disc brakes had been proven in race settings, and Lockhart sold an aftermarket disc brake and master cylinder that Harada had tried on a 450. It worked well but available brake pads all wore too quickly to meet his service-interval targets.

Harada knew that Honda had committed to unveiling the CB750 at the Tokyo Motor Show in November, and furthermore to have the first 750-Fours on dealer floors the following spring. That schedule was determined by a business strategy, which was to prevent the Triumph and BSA triples from ever getting a secure foothold in the key American market.

Honda CB750 disc brake
A disc brake was one of the 1969 Honda CB750K0's most important advancements. James Tyler Reed photo.

His dilemma was, he could choose a proven drum brake, which was after all what the Triumph and BSA triples had. A drum brake would not require much more testing, and would probably not present any manufacturing challenges. A disc brake would work better, and could easily be mocked up in time for the Tokyo show, but how long would it take to develop brake pads with the right combination of friction and wear? It could delay production.

Harada presented both options to Soichiro Honda, who unhesitatingly chose the disc.

We’ll open in Tokyo and then take the show to Vegas, baby

Honda displayed a remarkably complete and production-looking CB750 on its stand in Tokyo, and the sight of it brought the motorcycle world to a standstill. In hindsight, Honda was right to fit the show bike with a disc brake; that feature generated almost as much buzz as the across-the-frame four-cylinder motor — a type of motor that was familiar to race fans, and which had been used in a few limited-production bikes in Europe, but which had never been mass-produced for the motorcycle market.

The American market was the key, and the next big PR event took place the following January in Las Vegas, when American Honda Motor Company held its first big dealer meeting. Even Soichiro Honda was there, which was a big deal because he really didn’t like to leave the factory.

When AHM president Kihachiro Kawashima told the assembled dealers that the retail price would be $1,295, they burst into spontaneous applause; that was more than $1,000 less than any possible rival. Dealers immediately clamored for them — and Kawashima quickly raised the MSRP to $1,495!

Honda CB750

As a bonus, the announcement had the desired effect of slowing orders for the Triumph and BSA triples. Although few people realized it at the time, the impact of showing the CB750 in Tokyo and Vegas caused Kawasaki to immediately stop a secret project it had in the works, which was also a four-cylinder 750. (Kawasaki went back to the drawing board and, a few years later, introduced the 903 cc Z1.)

The response from dealers put Harada under even more pressure. He had to supervise the creation of an assembly line (actually, two lines) and fast-track the final stages of prototype and early production testing, especially the normally time-consuming reliability tests.

That procedure began immediately after the Las Vegas dealer show. In fact, the three prototypes Honda had flown to Vegas stayed right in Nevada, where a team of Honda engineers (accompanied by a few AHM technical staff) immediately rode them, revving the crap out them, for 5,000 miles over five days. The bikes, and Japanese and American technical staff, then flew back to Japan for much more reliability testing. I’ve read that even at this point the engineering team was only about 60 people.

Honda CB750 instruments
Instrumentation doesn't come much cleaner than this. 1969 Honda CB750K0. James Tyler Reed photo.

The manufacturing process illustrated another aspect of Harada’s design genius: Sure, the four-cylinder layout was inspired by Honda’s Grand Prix racers, but those motorcycles had pressed-up cranks rolling on needle bearings, and gear-driven, dual-overhead-cam, four-valve heads. By contrast and for simplicity, the CB750 had one-piece crank running in plain bearings, and a single chain-driven cam operating two valves per cylinder.

Honda’s factory in Saitama built an assembly line for motors, which were sent to Hamamatsu, where the rolling chassis were made. The first true production CB750K0 rolled off the line on March 15, 1969.

Honda CB750 engine
Early sandcast engines like this one bring big money today. 1969 Honda CB750K0. James Tyler Reed photo.

There was all the usual pain getting the lines up and running. At first, they were lucky to crate five bikes a day. But the flood of orders immediately meant that Honda could justify whatever it took to increase production. The initial forecast called for 1,500 bikes in 1969; by the end of the year Honda was shipping 1,500 a month.

Honda CB750A
Honda made few changes to the CB750 until the 1976 Honda CB750A with a semi-automatic transmission was introduced. Honda photo.

The CB750 changed everything (though it stayed largely the same)

The Triumph Trident and BSA Rocket 3 did beat the CB750 into the U.S. market, as Hansen had foretold. But the Honda had a disc brake, electric start, and a five-speed box with left-side shift, which were all popular with U.S. customers. And, it cost much less. No single thing killed off the once-great British motorcycle industry, but the single biggest thing was the 750-Four.

Around the time Honda dealers saw the CB750 in Vegas, Harley-Davidson’s controlling shareholders saw the writing on the wall. They sought the protection (and cash flow) of a bigger company.

Rodney C. Gott, the chairman of AMF and a lifelong Harley fan, came to the rescue. Although AMF is now reviled by the brotherhood of the bar and shield, I think it’s fair to say that in the first few years, Gott invested in the brand and modernized production. But Honda took too large a share of the U.S. market for large-displacement cycles, and when AMF couldn’t see a way forward, it tried to increase production without additional investment, which led to quality problems. That made Harleys look like even worse values compared to Hondas.

Honda CB750
1969 CB750K0. Honda photo.

The CB750 crippled some companies, for sure. But the bigger impacts were on the marketplace, where it completely changed customer expectations, and among Honda’s surviving rivals, who were forced to accept that the bar had been permanently raised. Foremost among those responses: In 1972, Kawasaki released the Z1 with dual overhead cams and a displacement of 903 cc. It became the new king of motorcycles, and Honda didn’t even really respond, perhaps because by then the company was focused on the new Civic car.

European manufacturers like Ducati and BMW couldn’t hope to compete with the Japanese on price, but Ducati upped its performance game with the bevel-drive, desmo 750GT in 1971. Then, in 1973, BMW presented the speedy, solid, and surprisingly stylish R90S.

Suzuki clung too long to two-stroke technology and then took a huge risk, introducing the RE5 "Wankel" in 1974. That was a foolish gamble, but when the company finally released its own across-the-frame four-stroke four-cylinder GS750 in 1977, it was probably the best-handling of the big Japanese bikes.

Ironically, Harada had told the original CB750 design team that they’d produce a single-cam version for about three years, then upgrade to a twin-cam design. Honda didn’t fit a twin-cam head until 1978.

Whether the CB750 was the very first superbike is arguable. (If you want to make that case for the Norton Commando, I won’t fight you.) But what’s certain is that it was the first affordable, reliable superbike. It did to the post-war motorcycle industry what the Model T had done to the pre-war auto industry. Which is to say, it changed the entire market from that moment it was unveiled, 50 years ago.