Birth of the Super Cub

    American Honda
    Sep 27, 2012
    The Open Road

In 1956, Soichiro Honda and the company’s Senior Managing Director, Takeo Fujisawa, traveled to Europe together. On the surface, their purpose was an observation trip but actually the two had an idea for a completely new product; they took this trip to substantiate it. The Honda Cub F-Type had gone out of production, and in Japan mopeds were growing in popularity, replacing the auxiliary engine for bicycles.

Upon their return to Japan, the two men assigned development of this new product to the engineering design staff. Yoshiro Harada, then Head of the frame engineering design section, would lead this project. He remembers, “The Old Man talked about the idea he had in his mind. It was close to a moped, but it would be different. As we went on, it gradually became more concrete. The Old Man would get to the engineering design room early in the morning and call out, ‘Hey, last night I thought of this,’ and everyone in the room would come over to see what was up. After a while he would squat down and start sketching his idea on the floor with chalk. While he was drawing, he would be thinking ahead, so he’d use his hand to rub out what he had drawn and start sketching again. The employees who surrounded him would all be quivering with tension as they listened. ‘The engine will be a four-stroke!’ The Old Man had come to really hate two-stroke engines. In the New Year season of 1957, we started development, beginning with the engine.”

Daiji Hoshino was in charge of the engine and recalls, “Nobody in the world was mass-producing anything like a 50cc four-stroke engine; if an engine was a 50cc, it had to be two-stroke. Mr. Honda would show up in the engineering design room every single day. I would be absorbed in working out some basic calculations, when I’d suddenly glance up and he would be standing behind me. He would often watch over my shoulder without my realizing it. Talk about turning up the heat! When we started drawing the engineering plans, it got even worse. For one thing, he could read blueprint drawings very quickly. He would take one glance and say, ‘This is no good,’ and put a rough pencil stroke right over a part I’d taken great pains to draw cleanly. He had very sharp intuition, so he could perceive problems instantly. There’s no doubt about it, his brain wasn’t like other people’s.

“We were worried about not getting sufficient power output. The only thing was to enlarge the intake and exhaust valves. But this was a 50cc engine so the surface area available in the cylinder head was too small. If we used standard 12mm-diameter spark plugs, we couldn’t increase the diameter of the valves. We decided to take a bold step and use 10mm plugs. To put it in Mr. Honda’s language, ‘Common sense is there in order for us to break through it.’ NGK, the plug manufacturer, was very positive about developing 10mm plugs. We got an output of 4.3 PS, so we ended up with about twice as much power as anybody else.” The engine was made a four-stroke. This was the crucial choice that determined the future of the Super Cub, a future still unfolding today.

Development of the clutch mechanism started at the same time as engine development. Harada recalls, “From the start, the Old Man was saying, ‘I want to make it so the noodle shop delivery boy can balance his tray on one hand and operate the bike with the other.’ In other words, a bike that would enable the rider to leave one hand free. That means the clutch wouldn’t be operated by hand.”

So the Super Cub employed an automatic centrifugal clutch. What required the team to take repeated pains, in particular, was the clutch disengagement mechanism; as many as eight different methods were tested.

Development of the body began in February as well. Harada handled the general supervision of everything from the engine to the styling. Motoo Nakajima was in charge of the front suspension team, and Futoshi Hasegawa’s team worked on the rear end and brakes. Kichinosuke Ando, who joined the team in June, supervised the frame and body team.

The bottom-link front suspension that Nakajima had begun working on was designed to be small and sleek. However, it had the comfortable ride and toughness needed for travel on bad roads. “It was important to give the Super Cub a friendly look; we didn’t want to make it seem too tough,” Nakajima comments. “We had to consider production costs too and make the suspension function adequately, so I think this is where we had the most difficult time.”

Ando remarks, “I joined the company in June 1957, when the Super Cub development was already in progress. What amazed me was that when the bike was completed, there weren’t any properly written specifications. We didn’t have blueprint drawings of the skeleton showing things like the length of the wheelbase, the caster angle, the trail and so on. Ordinarily, you base fabrication on those specifications, but Honda did the opposite. We built the skeleton and then wrote the specifications.

“The Old Man strictly demanded weight reduction. We trimmed and trimmed and finally got it down to 55 kilograms. We had good timing too. New materials like polyethylene were just coming out, and this was a time when manufacturing technologies were taking great leaps forward. Honda aggressively adopted methods suited to mass production, such as electric welding. On top of the brains that were in the group, I think this good timing was a major factor in the Super Cub’s success.”

Underlying the Super Cub’s success was the choice of 17-inch tires. Tires of this size were simply not being produced at that time. What was the reason for choosing the 17-inch size? Driving stability, the ability to drive across rough road surfaces, comfortable riding height, and appropriate distance from foot to ground when stopping the bike were among the conditions taken into consideration. This was the optimal tire size, and the decision was carried through Honda’s affirmation. Harada recalls, “The tire manufacturer didn’t go along at first; they would have been making 17-inch tires just for one Honda product model. It was the same story with the rim manufacturer. The result, though, is that they have been generously recompensed by the Super Cub’s sales.”

When April came, Honda began styling the body. The designer in charge of the Super Cub was a newcomer, Jozaburo Kimura. He had toured Honda’s Shirako Plant the year before graduating from university and had been so impressed by the energy there that he joined the company.

“It was practically like an ionizing reaction going on inside a beaker,” Kimura says. “Everyone was crackling with energy as they worked. I started working at Honda in November 1956, just when the top secret ‘Operation Special M’ had begun—the Super Cub development project. Something the Old Man was often saying around then made an impression on me: ‘Make it something that fits in your hand!’ At first I didn’t understand. After awhile, I figured out he meant he wanted to make motorcycles an intimate presence in people’s lives, something that anyone could use without fuss or worry. Make them like the tools you use with your hands.”

The standard practice in European mopeds was to place the fuel tank forward, but Mr. Honda did not agree: “This isn’t a motorcycle you ride from behind with your leg raised. This is a bike that you sit down on from the front. We want customers wearing skirts to buy this. Don’t put the tank where it gets in the way.”

The styling effort finally proceeded to the final mockup at the end of December. Honda said, “This isn’t a motorcycle. It isn’t a scooter, either.” Indeed, this mockup, finished to look exactly like an actual product, showed a two-wheeled vehicle with a new form that had never before existed.

Fujisawa was called in to see the new product. For about 15 minutes, Honda eloquently enumerated the unprecedented features to Fujisawa. Then he said, “Well, what do you think? How many of these do you think we can sell?” Fujisawa’s reply was, “Maybe about 30,000.” A year? “No,” said Fujisawa, “30,000 per month!” At this time, the aggregate number of units sold by all motorcycle manufacturers combined in Japan was somewhere around 40,000 a month.

The Super Cub was the first Honda product to utilize polyethylene on a large scale, from the front fenders on up. Harada recalls, “Using polyethylene was a great adventure. It was a new material just starting to gain popularity. There was no precedent for its use in the motor vehicle industry. We used it because the Old Man decided to use it. The riding performance of the Super Cub was raised that much higher because we had so many parts made of light polyethylene instead of heavy sheet steel. In the end, this material also turned out to be very effective in reducing our costs.” If Honda had followed tradition and made all those parts with steel, Harada says, the Super Cub might never have become such a success.

Development took the unusually long time, by Honda standards, of approximately one year and eight months from inception. The Super Cub went on sale in August 1958. Mr. Honda is said to have made the Super Cub entirely from the customer’s perspective. From its engine and shape to its ease of riding, ease of use, durability and economy, everything had “put the customer satisfaction first.”

When Mr. Honda test-rode the bike, he deliberately went through puddles in the road to check how the mud would splash up on him. Having been brought to completion in this way, it was as though the Super Cub itself was the Honda philosophy turned into a bike.

Honda Powersports
Top Articles
Click an article’s title below to view:
Trending Topics

View past articles. Select a year and month.

Get Social

Upcoming Events
  • Jul 01, 2018
  • MotoGP
    Assen, Netherlands
  • Jul 15, 2018
  • MotoGP
    Hohenstein-Ernstthal, Germany
  • Aug 05, 2018
  • MotoGP
    Brno, Czech Republic
  • Aug 12, 2018
  • MotoGP
    Spielberg, Austria
  • Aug 26, 2018
  • MotoGP
    Silverstone, England
  • Sep 09, 2018
  • MotoGP
    Misano Adriatico, Italy
  • Sep 23, 2018
  • MotoGP
    Alcaniz, Spain
  • Oct 07, 2018
  • MotoGP
    Buriram, Thailand
  • Oct 21, 2018
  • MotoGP
    Motegi, Japan
  • Oct 28, 2018
  • MotoGP
    Phillip Island, Australia