Notable engineers - at #2, Walter Kaaden – doubled the horsepower of two-stroke motors

As the head of engineering and racing at MZ in communist-controlled East Germany, Kaaden faced challenges that dwarfed those of engineers on the other side of the iron curtain – materials shortages, travel restrictions, and a dispirited workforce, to name just a few. Despite those handicaps, in the late 1950s and early ‘60s, he made some of the world’s fastest motorcycles. His secret was the expansion-chamber exhaust, which doubled the power output of two-stroke motors. 

For years, Kaaden (right) alone understood the arcane math of expansion-chamber design. Then one of his riders, Ernst Degner, also seen in this pic, escaped to the west bringing the knowledge with him. The next year, Degner rode a Suzuki (bearing a conspicuous resemblance to an MZ) to a world title. Virtually every two-stroke motor built since then used an exhaust based on Kaaden’s research.

Notable engineer countdown - at #3, Yoshiro Harada – led development of the Honda CB750

It is impossible to overstate the impact of the first truly mass-production four-cylinder, disc-braked motorcycle. When the CB750 was unveiled at the 1968 Tokyo Motor Show consumers gasped and the world press (and rival companies) were taken by surprise. It had been developed by a small team working in total secrecy. The team leader was Yoshiro Harada.
 

Harada toured the United States a few years earlier, meeting American riders and Honda motorcycle dealers when Honda introduced the CB450 twin. That bike had sold poorly in America despite the fact that it outperformed much bigger British twins. He realized that the U.S. with its wide-open spaces, would embrace a big, powerful bike. The decision to make it 750cc was based on the knowledge that Triumph and BSA were developing 750cc triples. It would be a four-cylinder bike to evoke Honda’s Grand Prix racing heritage (and one-up the English.) Finally, it would produce at least 67 horsepower, since the most powerful Harleys made 66!

The design was a breakthrough, but so was the design process. Harada’s team was able to prototype the bike in record time and ensure an efficient manufacturing process by making revolutionary use of computer-assisted-design and computer-assisted-manufacturing. The end result established Honda once and for all as the world’s pre-eminent motorcycle manufacturer.

Notable engineers countdown - at #4, Edward Turner gave birth to twins

Turner (1901-'73) was born on the day King Edward was crowned, which was appropriate as Turner himself became British motorcycle “royalty.” When he was hired as Triumph’s General Manager and Chief Designer he was offered a lavish salary and 5% of the company stock and profits. 


Soon after joining Triumph, he designed the 1937 Speed Twin. In truth, the motor was not strikingly innovative – some say Turner just copied its basic architecture from the Riley 9 car in which he was chauffeured to work. However, it made elegant use of existing technology and established the basic design for all British twins between the end of WWII and the 1970s. For much of that time, bikes like the Triumph Bonneville were the most sought-after models in the market.

Notable engineer countdown - at #5, Phil Vincent

Phil Vincent, making what must have been about his last stand, at the Earl's Court Motorcycle Show in 1954.

Between the late 1920s and mid-‘50s, Vincent’s motorcycles were among the fastest and most advanced on the market. He was the first major manufacturer to relocate rear shocks to something like the position now used on virtually all modern bikes. But the most striking aspect of his design was the way he virtually did away with the frame altogether. After WWII when high-quality steel tubing, suitable for use in motorcycle frames, was in short supply in Britain, he attached the steering head to the front of his massive V-twin motor and pivoted the swingarm from the back of it. Today’s manufacturers are still catching up to that idea.

Notable engineer countdown - at #6, Fabio Taglioni – adapted desmodromic valves to motorcycles

I'm sorry, I couln't resist. I'm told this guy's an avid motorcyclist. For a photo of the real Fabio Taglioni, go here.

Taglioni was the chief designer at Ducati from 1954-’89. Although many “Ducatisti” would like to believe that Ducati invented the “desmo” valve system (using a second cam to close the valves, instead of valve springs) the patent was held by Daimler-Benz. Still, it was Taglioni who realized that the system would benefit fast-revving motorcycle engines which, in the 1950s, were limited by the reliability of valve springs. When he mated two Ducati 350cc singles to create the first Ducati 90-degree V-twin, he created one of motorcycling’s truly iconic designs.

Notable engineer countdown - at #7, Etsuo Yokouchi – Suzuki GSX-R750 design team leader

"To infinity, and beyond!" Etsuo Yokouchi, in a photo taken about a 15 years after unveiling the first Suzuki GSX-R750, which was launched at the 1984 Cologne motorcycle show.

Notable engineer countdown - at #8, Tadao Baba – creator of the Honda Fireblade

Not to be confused with the guru known to millions as simply 'Baba', Honda's Tadao Baba brought sweet handling and smokin' performance together to create the modern 'liter-class'.

Thanks to the GSX-R750, Suzuki stole a march on Honda in the performance market. Then Suzuki introduced a larger and even faster 1100cc “gixxer.” That bike, however, didn’t handle nearly so well. Baba, an engineer working at Honda saw the opportunity to create a motorcycle with open-class power and 750-class handling. When it was introduced in 1992, the ‘blade amply reached those goals: it weighed about 410 pounds and produced nearly 125 horsepower. Baba’s creation completely changed the expectations of open class riders, who had always wanted acceleration and top speed but never knew they could have handling too.

Notable engineer countdown - at #9, William S. Harley – created Harley-Davidson's first V-twin

William S. Harley, 1880-1943

Bill Harley drew up a single-cylinder motor suitable for powering a bicycle in 1901, at the age of 21. Two years later he partnered with Arthur Davidson to produce a racing motorcycle; that first Harley-Davidson was born in a 150-square foot shed. Harley graduated from the University of Wisconsin with a degree in mechanical engineering in 1907. By that time, two more Davidson brothers had joined the partnership and the company was firmly established. Harley designed and prototyped the first H-D V-twin motor that year, too. Whether you love or hate what that design led to, there's no denying the fact that William S. Harley is the single individual who ended up having the largest influence on the shape of the American motorcycle. To learn more about him start here.

Notable engineer countdown - 10 who left their mark on motorcycling

Before the modern motorcycle could take shape, it first took shape in the minds of engineers and designers. Picking the ten most deserving for this list is a task guaranteed to infuriate some readers, but these guys championed ideas and influenced whole categories and markets.

In position #10, Erik Buell – engineering iconoclast

"More cheese, Gromit?" Wisconson's Erik Buell does his best imitation of another noted cheesehead. This was at Daytona in 2006, when the star-crossed XBRR took 'modifying the cases' to extremes. Rules are made for stretching.

Although Harley-Davidson’s air-cooled, pushrod V-twin motors are not an obvious choice as powerplants, Erik Buell’s determination to produce a mass-market American sport bike was admirable and he’s proven to be an extremely creative engineer. His use of shock absorber springs that operate in tension, frames that carry fuel and swingarms that carry oil, and rim-mounted brake discs are just a few of the inventions that may, some day, be found on other brands of motorcycle. 


After Buell was, almost literally, thrown out into the cold by Harley-Davidson, he set up a small shop and went back to his roots, selling and servicing production race bikes. He plans to release a new streetbike, the EBR 1190RS, soon.