The invention of the first two-wheeler is a much-debated issue. "Who invented the first motorcycle?" may seem like a simple question, but the answer is quite complicated.

Two-wheelers owe their descent to the "safety" bicycle, i.e., bicycles with front and rear wheels of the same size, with a pedal crank mechanism to drive the rear wheel. Those bicycles, in turn descended from high-wheel bicycles. The high-wheelers descended from an early type of pushbike, without pedals, propelled by the rider's feet pushing against the ground. These appeared around 1800, used iron-banded wagon wheels, and were called "bone-crushers," both for their jarring ride, and their tendency to toss their riders.

Gottlieb Daimler (who later teamed up with Karl Benz to form the Daimler-Benz Corporation) is credited with building the first motorcycle in 1885, one wheel in the front and one in the back, although it had a smaller spring-loaded outrigger wheel on each side. It was constructed mostly of wood, the wheels were of the iron-banded wooden-spoked wagon-type, it definitely had a "bone-crusher" chassis!

This two-wheeler was powered by a single-cylinder Otto-cycle engine, and may have had a spray-type carburetor. (Wilhelm Maybach, Daimler's assistant, was working on the invention of the spray carburetor at the time). If two wheels with steam propulsion can be called a motorcycle, then the first one may have been American.

One such machine was demonstrated at fairs and circuses in the eastern US in 1867. This was built by one Sylvester Howard Roper of Roxbury, Massachusetts. There is an existing example of a Roper machine, dated 1869. A charcoal-fired two-cylinder engine, whose connecting rods directly drive a crank on the rear wheel, powers it. This machine predates the invention of the safety bicycle by many years, so its chassis is also based on the "bone-crusher" bike.