The small bicycle wheel, something close to 16 or 20 inches, has been with us for some time. When society called a machine with a 50-inch front wheel a bicycle, only the rear wheel was small, and it didn’t get much attention.
It was just a wheel: a hub, some spokes and a rim curved to accept a solid rubber tire (held by compression against the rim by the tensioned wire inside). It had no brake and no gears. It simply rolled behind the wheel in front of it and kept the rider from falling backward.
Falling forward was a very different and easily realized proposition. With the center of mass very nearly over the front cranks, an unseen road defect could cause the machine and rider to pitch forward. The result was aptly described as a “header.”
Likewise, because of the machine’s geometry, the spoon brake—a curved piece of metal motivated through a hand lever to push against the top of the front tire—was nearly useless, its lack of utility matched only by the sheer primitive nature of its design.
However, it was the perfect brake for a high-wheeled bicycle. A better brake would have led only to more frequent and spectacular headers.
The drive train was just as unsophisticated. There was only one gear, defined as the diameter of the driven wheel, and no possibility of coasting. If the cranks moved forward, the front wheel rotated. Pushing back against the movement of the pedals allowed you to slow the machine, assuming you weren’t flying downhill at the time.
For instance, if you were riding downhill toward the traffic lights on East Peoria’s Springfield Road in the 1980s, you took it as slow as possible: arms fully extended as you leaned backward, pushing back against the pedals enough to keep the bicycle from running away, but not so hard as to pitch forward over the handlebars. Even so, the rear wheel would rise with each backwards push, transforming the bicycle into a unicycle with a rotary flag every 25 inches or so.
Back on level ground in the 19th century, if both wheels had been the same size as the rear, the bicycle would have been very slow, not only because of the low direct-drive gear, but also because the rider would have been forced to work hard just to keep the small wheels moving over the rough roads of the day.
As it was, with front wheels of adult bicycles ranging from 46 to 60 inches in diameter, the velocity of the machine wasn’t really affected by the small rear wheel because that wheel was so lightly loaded.
As the bicycle evolved to assume its current configuration—both high wheelers and new-fangled safety bicycles were featured in Peoria’s Rouse, Hazard & Co. catalog of 1889–90—the small wheel was quickly jettisoned in favor of 30-inch hoops.
It would be a few more years before air-filled tires were adopted, and by that time the “proper size” of the wheel had been effectively established by the solid-tired safety.
With the exception of early recumbents, cargo carriers and mysterious machines such as Le Petit Bi, small wheels on adult bicycles would disappear until Moulton introduced his dual-suspension bicycles in the 1960s.