Introduction to the Wheel
The wheel has revolutionized the history of mankind. Without it, there would be no carts, carriages, trains or wheelbarrows. Its design – a disc that rotates on its axis – has evolved over time, in response to human needs and the availability of new materials.
Wheel design and operation
To work properly, a wheel must rotate freely around its axis. To achieve this, the axle must be fixed in the center of the wheel, thus ensuring continuous movement. The wheel axle and center hole must be perpendicular to the ground to limit friction. The axle must also be as thin as possible to reduce the friction surface, yet strong enough to support the vehicle’s load.
History and Evolution of the Wheel
The oldest known wheels date back to 3500 BC. The Sumerian civilization in southern Iraq used logs to move heavy loads such as carved stones or megaliths. This object has undergone numerous improvements and is now widely used.
The First Wheels
The first robust but heavy wheels were solid, with a central hole for the axle. They offered limited speed and maneuverability. They gradually evolved into a lighter, sturdier model.
The Invention of the Spoked Wheel
Later, parts of the wheel were hollowed out to reduce weight and make way for spokes around 2000 BC. The lighter spoked wheel enabled much higher speeds. This last invention led to the invention of the chariot, used in ancient Egypt for hunting, parades and battlefields.
Wheel reinforcement and adaptation
Iron rims were added later to reinforce Celtic chariots. Spoked wooden wheels with iron rims were the norm for centuries, and remained unchanged until 1802. The first metal-spoked wheel was manufactured and patented by G.F. Bauer in 1802.
The Wheel in the Modern World
A few years later, metal spokes adopted the shape found on bicycles today. To protect the wheels from impact, rubber protectors have been added, marking the birth of the tire.