Orbital wheel

The wheel can be considered one of the most important inventions important in the history of mankind. Its principle has remained the same for thousands of years. But in 1989, Franco Sbarro surprised everyone by reinventing the wheel.

The idea

Franco Sbarro's orbital wheel, a hubless wheel, is based on a very simple idea: the stresses applied to a wheel are at ground level, on the outer periphery. A wheel without an axle supports the vehicle at its lowest point. The center of gravity is lowered for better roadholding.

The wheel has two components:
- a rotating part comprising the tire, a tubular rim matching the inner face of the tire, and a brake ring;
- a fixed part, articulated to the inner tread of the wheel, where the connecting triangles, steering bar and braking clamps are mounted.

From theory to practice

This orbital wheel required a very large-diameter bearing. Franco Sbarro turned to SKF, a Swedish company specializing in bearings. Then, with Dominique Mottas, Franco Sbarro founded Sbarro Mottas Engineering, which set up the Osmos (Original Sbarro Mottas Orbital System) program, culminating in the presentation of the Osmos coupé and three particularly spectacular motorcycles.

"Orbital" motorcycles

More than the Osmos coupé, it was the motorcycles equipped with the orbital wheel that caused a sensation. It has to be said that the absence of a hub is more "visible" on a two-wheeler than on a car.

- The first bike, in white, is surely the purest. On the right-hand side, there's nothing to suggest any connection between the bike and its wheels;
- the second bike, red, has a visible front linkage arm that conceals the lower part of the wheel. At the rear, it has a conventional wheel with hub and chain;
- the third bike is more of an educational tool. The bodywork is only hinted at with metal wires, allowing a clear view of the whole orbital wheel link arm.
It's worth noting that another astonishing machine was equipped with the orbital wheel: the Aero. This sidecar, launched in 2000 to promote the watch inspired by the orbital wheel, reappeared at the Mondial de l'Automobile and the Essen Motor Show in 2008.