The machine that people could actually ride
By the early 1880s, bicycles existed in large numbers, but they were not for everyone. The high-wheeler was fast and elegant, but a rider sat high above the ground on a large front wheel, and a collision with a small obstacle could throw them forward. The riders who accepted this were mostly young, athletic and wealthy enough to buy a costly machine. The safety bicycle changed the target audience, and that is why historians often treat it as the point where the bicycle became a transport technology instead of a sport for a few.
What “safety” meant
The word “safety” was a marketing term as well as a description. It referred to the lower position of the rider, who could put a foot on the ground and was less likely to be thrown forward. The design avoided the combination of a high seat and a pedal-driven front wheel. It was safer in relative terms, and there is no suggestion in the name that riding became risk-free.
Early safeties
The route to the new design was gradual. Makers tried several ways of lowering the rider while keeping speed. Some built “dwarf” high-wheelers with smaller front wheels and gearing in the hub, or levers that drove the rear wheel. In 1879, H. J. Lawson’s Bicyclette used a chain to the rear wheel. Other early machines, with names such as the Kangaroo, used geared front wheels. Each of these had flaws and none was widely adopted.
The design that is most often treated as the breakthrough was the Rover safety bicycle, introduced in 1885 by John Kemp Starley and his partner William Sutton in Coventry. It had two wheels of about the same size, the front steered by handlebars and the rear driven by a chain from the pedals. The rider sat between the wheels, and the frame was built so that the legs were not too far from the ground. It was by no means the only chain-driven bicycle of its time, and it was not the very first. It is remembered because it combined the pieces in a form that worked well and sold well.
Why equal wheels worked
With a chain between pedals and wheel, wheel size no longer set speed. Gear ratio did. A small chainring in front of a larger sprocket gives a low gear, and a larger chainring gives a higher one. Because of this, makers could choose wheels based on other considerations, such as weight, strength and the rider’s comfort. A smaller wheel was easier to build and lighter, and a rider could still reach good speeds by choosing the gear.
Equal-sized wheels also gave balanced handling. The weight of the rider was spread between the two wheels, and the center of gravity was low, so that a sudden stop was unlikely to pitch the rider forward.
The frame
The first safety bicycles had frames made of tubes joined in various arrangements. Over the following years, the diamond frame emerged as a standard. It consisted of two triangles: a front triangle formed by the top tube, down tube and seat tube, and a rear triangle for the rear wheel. Triangles are stiff shapes, and a frame of light steel tubing could carry a rider’s weight at low cost. The result was lighter than the high-wheeler’s backbone and could be built in large numbers.
Different frame styles served different riders. For women who wore long skirts, makers introduced dropped or open frames in which the top tube was lowered or removed so that the rider could mount without lifting a leg over a high bar. These “step-through” frames remained common on utility bicycles.
Wheels and tires
The new bicycles used spoked wheels made of thin steel wire, which could be tensioned to make the wheel strong and light. The development of these wheels, together with wire drawing technology, helped reduce weight. Tires started as solid rubber but changed in the late 1880s with the arrival of the air-filled pneumatic tire, which made the ride much smoother on rough roads. The combination of the safety design and pneumatic tires was a strong one, and it helped to set off the cycling craze of the 1890s.
Production and price
Safeties were also easier to make in numbers. Their parts were smaller and simpler, and the push toward interchangeable parts, a path that later led toward assembly line production in other industries, helped bring prices down. Cheaper machines meant that clerks, shop workers and others could consider buying a bicycle. Used bicycles and installment plans also expanded the market, though the details varied from place to place.
Beyond the bicycle
The safety bicycle’s layout and skills influenced other machines. Early automobiles often used tubular frames, chain drive, wire wheels and pneumatic tires borrowed from the cycle trade, and some cycle manufacturers became car makers. The Wright brothers, who ran a cycle business in Ohio, used chain drive in their first powered aircraft. These links are well documented, though they do not mean that bicycles alone created cars or airplanes.
A lasting layout
The layout of the safety bicycle, with two equal wheels, a diamond frame and chain drive to the rear wheel, has proved remarkably durable. Materials and components have changed, but the basic arrangement can be recognized in bicycles made more than a century later. It stands as one of the clearest examples of a design settling into a form that works for most people.