In 1925 the German magazine Echo Continental ran a feature about a new “ABC mono-cycle”:
The ABC-cycle was given that name by the manufacturer because it is as simple as the ABC and can be operated without prior knowledge by anyone, especially a woman. The vehicle is designed as a mono-cycle, the motor, a directionless three-stroke 2 hp. 1.5 Cylinder “Gnomissima” engine is under the seat and pleasingly warms or cools the driver. A kickstarter and convenient footrests make this motorbike particularly popular with women.
As tires only the highly reliable antiskid “Continental-Kraftradreifen” are to be used. The profile of these tires remains unaltered, as they have proven themselves highly reliable on smooth asphalt roads.
Echo Continental was the trade publication of the auto and truck parts manufacturer Continental AG. This feature essentially served as a plug for the company’s “Continental-Kraftradreifen” tires — which makes it one of the earliest examples of a spoof April Fool ad.
(via The Museum of Hoaxes)