Form follows function

By Matt Stone

In 1896, architect Louis Sullivan coined the famous maxim, ‘form follows function’. 

His maxim can certainly be applied to the motorcycle. Its form has closely followed its function since the earliest prototypes took to the road.

ACE Four
ACE Four USA, 1920–1927, four cylinder in-line ~1220cc. Photo: Ben Branch / Silodrome.
See also main picture gallery below.

The world’s first motorcycle is generally attributed to Gottlieb Daimler. His Reitwagen (‘riding car’), from 1885, was powered by a small single-cylinder engine.

The frame of the Reitwagen was constructed mostly of wood. Author Melissa Holbrook Pierson, in her book The Perfect Vehicle, says it resembles  ‘…an instrument of torture’.

However, it wasn’t long before other designers began refining the concept.

The early years

In 1894, Hildebrand & Wolfmüller started producing the first series production motorcycle, which sold around two thousand units.

Others manufacturers followed. Among the general public, the motorcycle became popular as a practical mode of transport. And of course, a few brave souls started pushing the limits.

By 1907, American aviation pioneer Glenn Curtiss had mounted a 4-litre V8 aircraft engine into a specially designed frame. He achieved an unofficial record of 136.36 mph (219.45 km/h), becoming known as ‘the world’s fastest man’.

Manufacturers competed to attract attention with models ranging from simple runabouts, to sophisticated and expensive sports machines.

A fine example of the latter is the ACE Four from 1920. It was designed by American engineer William G. Henderson, known for his innovative four-cylinder engines. He paid great attention to aesthetic details, and the ACE Four has elegantly flowing lines. It’s easy to understand why it became known as ‘the Duesenberg of motorcycles’.

Unfortunately, on 11 December 1922, Henderson was killed after being struck by a car when test riding one of his machines. Without his creative spirit, the ACE business began to struggle, and by the late 1920s had failed.

ACE’s larger competitor, the Indian company, took over the business, and the bike continued in production as the Indian Four.

Over the years, the frame was beefed up to suit police and military riders, so lost much of its sporting elegance. But it sold well enough to remain in production until 1942. 

If you’re a fan of film noir, you’ll sometimes see police riders dashing to crime scenes on these bikes.

Between the wars

In the 1920s and 30s, manufacturers around the world were pushing the envelope, in performance and style.

The German company BMW created an Art Deco masterpiece with its streamlined R7 concept of 1934. Only one R7 was ever built, and it’s recently been restored.

In Britain, the Vincent company had made its name with bikes powered by a 500cc single cylinder engine. Its Australian engineer, Phil Irving, was inspired to combine two of those cylinders into a potent 1000cc V-twin, which he mounted into an experimental frame.

After a series of promising test rides, Vincent bosses gave the go-ahead. The big V-twin sold well, and was refined and updated over the years – culminating in the now legendary post-war Black Shadow. It was claimed to be the world’s fastest production bike, and could reach 125 mph (200kmh).

Captivated by its charms, but cognisant of the dangers, novelist Hunter S. Thompson observed that ‘…there are not many life members of the Vincent Black Shadow Society’.

After World War II

This was an exciting era for British manufacturers such as Norton, Triumph and BSA, highly respected for their singles and twins. There were innovative engine formats too – like Ariel with its powerful yet tractable 1000cc Square Four

Italy was another hotbed of innovation, on the road and racetrack.

During the 1950s, Italian 500cc racing bikes typically had an air-cooled in-line four-cylinder engine, mounted transversely across the frame.

But Moto Guzzi’s chief engineer, Giulio Cesare Carcano, was seeking more power. His solution was an audacious liquid-cooled V8. With eight tiny pistons, its reciprocating parts were lighter than a four’s, delivering maximum power at over 12,000 revolutions per minute.

The brutish machine showed great promise, but the factory withdrew from racing before it could be fully developed.

When it came to road bikes, Italian manufacturers were constantly looking for ways to improve their designs. And by the late 1960s, there were some highly refined models to choose from.

The small Laverda factory was aiming at the American market with its finely crafted fast parallel twins. Moto Guzzi’s approach was a little more sedate – despite its racing heritage – and its wonderful shaft drive V-twins were appreciated by touring riders.

Meanwhile, MV Agusta introduced the world’s first production motorcycle with a four cylinder engine mounted transversely. Unfortunately the 600cc bike was expensive, its styling was ungainly, and sales were poor (although it did lay the groundwork for the magnificent 750S America).

During this period, Ducati was still finding its feet, but offered several fast singles of up to 450cc.

In Germany, manufacturers hadn’t generally been as adventurous as the Italians, but produced some fine machines. Since the 1920s, BMW singles and flat twins had been known for their superb engineering – but tended to be stodgy and woefully underpowered.

The Japanese onslaught

Little did the Europeans know – at the end of the 1960s, the industry was about to be turned on its head.

With the increasing popularity of small Japanese bikes, Honda and Kawasaki had both begun developing larger models. They also realised their noisy and smoky (but exhilarating) two-stroke engines were on borrowed time.

In 1969, Honda created a sensation with the CB750 Dream, a highly capable four-cylinder sports bike.

It was a genuine all-rounder. Docile and tractable for commuting during the week – but perfect for unleashing enthusiastically on weekends. And unlike British bikes of the day, it was reliable and didn’t leak oil.

Honda had set a new benchmark. Taken by surprise, Kawasaki went back to the drawing board. They took their time but returned with a vengeance. The Z1 of 1972 proved to be formidable on road and racetrack.

Suzuki was late to the four cylinder game, and its first GS models of the late 1970s were refined versions of Kawasaki’s ideas. However, in the subsequent decades, the company would introduce many innovations of its own.

European manufacturers were blind-sided, and the British industry all but collapsed. In Italy, many manufacturers also struggled, and some bit the dust or were absorbed by conglomerates.

A notable example being Laverda, whose brawny triples were greatly admired, but which sadly went into terminal decline.

A time of great change

Very slowly, BMW started updating its conservative designs. It created a stir in 1973 with a new flagship sports tourer, the R90S. It was quite fast, and even did surprisingly well on the track against Japanese superbikes.

The R90S was styled by Hans Muth, and had the looks to match its performance. Although Muth’s true genius wouldn’t emerge until some years later – with his razor sharp weapon for Suzuki, the Katana.

Also in the early 1970s, Ducati released its exquisite 750 Super Sport, which helped to revive the marque’s fortunes. Visually, it was something you could park in your lounge room. And it had the performance and handling to match its looks.

In America, Harley Davidson managed to stay in business by sticking to very traditional designs. These appealed to a dedicated but ageing group of enthusiasts.

Eventually, by the early years of the 21st century, the European industry had recovered a degree – and even some defunct marques like Triumph had made a comeback. 

But today the industry has shrunk, globally, and the Japanese remain hard to beat.

In more than a century, the basic form of the motorcycle hasn’t changed much. Neither has its function: to enjoy travelling as quickly as possible (while arriving in one piece).