Riding a preposterous bicycle, Chicago, 1948. (Photo by Wallace Kirkland/Time & Life Pictures)

Gangbusters Bike mounts 13 shotguns, two revolvers, six bayonets, flare gun, 1948. (Photo by Wallace Kirkland/Time & Life Pictures)

Chicago, 1948. (Photo by Wallace Kirkland/Time & Life Pictures)

Ice Bike, with protective mittens on handles, is Joe Steinlauf's own solution to Chicago's icy winter streets, 1948. (Photo by Wallace Kirkland/Time & Life Pictures)

Chicago, 1948. (Photo by Wallace Kirkland/Time & Life Pictures)

Chicago, 1948. (Photo by Wallace Kirkland/Time & Life Pictures)

Bedstead Bike was dreamed up by Joe Steinlauf, who got the idea while lying around in bed one morning, 1948. (Photo by Wallace Kirkland/Time & Life Pictures)

Only springs connect rear of Maurice Steinlauf's bike with roving front wheel, 1948. (Photo by Wallace Kirkland/Time & Life Pictures)

Uno-Wheel, if braked suddenly, has been known to spin its rider round and round inside the big main wheel, 1948. (Photo by Wallace Kirkland/Time & Life Pictures)

Square-wheeled bike held by Bernard Steinlauf was built by son Dave after seeing a bicycle wreck, 1948. (Photo by Wallace Kirkland/Time & Life Pictures)

Four-man bicycle is powered by five chains and has brakes on both its wheels, 1948. The bike was built by Art Rothschild (top position) who broke three ribs while learning how to ride it. (Photo by Wallace Kirkland/Time & Life Pictures)

Chicago bicycle dealer Andy Koslow rides a tiny bike built by a former vaudevillian, 1948. “This helps limber up his left leg”, LIFE wrote, “which, as a former motorcycle racer, he broke seven times”. (Photo by Wallace Kirkland/Time & Life Pictures)