Dynasphere Monowheel

Until now, you have for certain read a lot of articles about cars with four, three and even two wheels. However, the current material has been prepared on a much more exotic topic, since now we will describe a rare, even exceptional invention in mechanical engineering, the monowheel.

The concept of the monowheel

Strangely enough, the idea of ​​using only one wheel in moving carriages originated about a century and a half ago and has already undergone several stages of development, including its renaissance. However, the fact that now we can all acquire the Airwheel single-wheel platform with a tiny power reserve does not mean that such projects have ceased to develop. On the contrary, even world brands have joined their development, which already hints at the prospects for the future. In the meantime, it is also suggested for the young motorists to get acquainted with how to rent a car under 25.


A few decades after the appearance of the first cars on the road, people began to think about changing their design radically. Dr. Purves developed the Dynasphere in 1932. His advertisement stated that this is the transport of the future. A wide carrier frame was used in the construction to overcome the problem of low stability of one-wheeled vehicles. The result was a three-meter steel wheel weighing about 450 kg. Dr. Purves tried to replace the entire automotive industry on the planet with its help.

Purves planned a whole line of machines of different sizes, but the matter was limited to prototypes. Despite many questions, its ridiculous appearance and the low speed (40 km /h), the Dynasphere worked very well, and was ready to make a revolution on the road.

The monowheel check proved that it was even more stable than suggested by its creator. The steering was completely absent, and to set the trajectory of this vehicle at a maximum speed, the driver had to deviate to the right or left, thereby shifting the center of gravity of the Dynasphere. Making such movement was very dangerous. Long and short of it, the selling of this vehicle was stopped for obvious reasons.

However, Purves was not only a fan of spherical journeys – a practical streak was also present in his character. Proud of his discovery, he modernized Dynasphere, having developed a platform for transporting five or even eight people! Such capacity was impressive, but the doctor did not manage to fully equip the crew for new tests.


With all its grotesque and clumsiness, Dynasphere significantly accelerated the development of monocycles. After cutting the ball from two sides relative to the center, Dr. Purves eliminated the main drawback of such a transport – its instability.

The Dynasphere vehicle was manufactured in several copies of two types:

The first option.

It was a single-seater version, driven by a 2.5-horsepower gasoline engine, which allowed this huge wheel to accelerate to a speed of 40 km/h (as it has been mentioned before). A single-seater version, driven by an electric motor, was also made. The only passenger, who was the driver at the same time, was placed inside this wheel on a special platform, where the engine was also located, sliding on the internal surface. To make turns, the driver had to deviate to the right or left, shifting the center of gravity of the entire unit and hoping for no obstacles in the way.

The second option.

The doctor decided to simplify the process of driving the monowheel. This made it possible to control the movement of the Dynasphere as in a conventional car. In other world, with the help of the steering wheel. The second version of the Dynasphere was a double-seater version, driven by a 6-horsepower gasoline engine. The platform, on which the driver, the passenger and the engine were located, was equipped with an adjustable tilt angle relative to the wheel, which made it possible to control the direction of Dynasphere by turning steering wheel. This petrol version was 3 meters in diameter, equipped with a ‘Douglas’ air-cooled 2-cylinder engine and weighed a total of about 450 kg.


Looking at the pictures and at the name of the monowheel, one may wonder why the word “sphere” appeared in the name of the device, which in shape resembles a ring or bagel. It turns out that the outer surface of the Dynasphere is a part of a sphere. This is what can be obtained if the sides of the ball are cut off parallel to its center. With the help of this trick, Dr. Purves managed to get rid of the main shortcoming of unicycles – their instability.