Back to Inspiration page 1
Motor Fly (1919-1920)

At the end of what we use to name " the great war ", Gabriel Voisin looks how to reconvert his production units.

As evoked besides, he has a project of prefabricated houses, but the sector of the individual transport seems to tempt him via various aspects.

In 1919, he applies for the patent #120.473, concerning a " driving wheel allowing the conversion of a bicycle in light motorcycle ", then in 1920 the patent #513.941, where the idea is improved by a system allowing two speeds. It is the Motor Fly.


The idea is to replace the back wheel of a common bike, by a flasked aluminum wheel, on which acts an engine fixed to the frame and developing a fantastic 1,25 horse!

A 2,5 liter fuel tank, is fixed to the frame, feeding the mechanic. The transmission to the wheel is initially made through a pebble, then two, offering two speeds by the operating of the adequate control lever.

The system is declutchable, to allow a normal use of the bicycle, in particular in the descents. With a suppposed autonomy about 80 kilometers, here is which authorize the cyclist to widen his range at a lower cost.


To praise the virtues of its creation Gabriel Voisin's company published a catalog, ancestor of our technical manual, describing, with many characteristic details and other advice of use of the machine, for example:

" ...always maintain the speed under 25 kph. To exceed this speed constitutes a danger, bicycles, even road model, not being planned for the important efforts which result from this speed ".

Or also: " never grease the leather of the driving crown wheel", one can imagine easily why!

The specialist publications also made the echo of this invention and " The Charles Faroux's " La Vie Automobile " dedicated it its issue #705 of May 10th, 1920.
The Automobile Life #05 of May 10th, 1920

Obviously, this kind of vehicle using a transmission by pebble reminds inevitably the famous " Vélosolex "; where was the inspiration, on one side or on the other one?

Misters Goudard and Mennesson, founders of the famous mopeds company have apparently a length beforehand, because it is at the end of 1917 that a patent is deposited for an auxiliary engine placed at the central level of a rear wheel.

But this invention will not be followed by real marketing, at least not before the 40s, and in a different configuration.

The first Vélosolex prototype
Did Gabriel Voisin hear about this project, and was he inspired by it? Do not we say that great minds think alike?


Documents MotorFly: collection PMA - Information and photos Solesx: Solex'in - the excellent Benoit Suzanne site

Back to Inspiration page 1