Wheel
The oldest surviving wooden wheel and axle combination dates to between 3340 and 3030 BCE. Archaeologists discovered this artifact at Stare Gmajne near Ljubljana in Slovenia, now known as the Ljubljana Marshes Wheel. This find predates other evidence of wheeled transport by several centuries. Earlier hints exist in the form of miniature clay wheels found north of the Black Sea before 4000 BCE. These small objects suggest that people were experimenting with rolling mechanisms long before they built full-sized wagons.
Depictions of wheeled vehicles appear on clay tablets from Uruk in Mesopotamia around 3500 to 3350 BCE. A Funnelbeaker culture settlement in southern Poland yielded a Bronocice clay pot showing a wheeled vehicle dated between 3631 and 3380 BCE. Evidence also emerged from Northern Germany dating back to around 3400 BCE. The invention likely occurred during the late Neolithic period alongside advances in pottery making. Some historians argue that the technology diffused from the Near East into Europe around the mid-4th millennium BCE.
Early wheels were simple solid disks carved from horizontal slices of tree trunks. These wooden discs often proved inferior due to uneven grain structures within the wood. Craftsmen later developed spoked wheels which allowed for lighter and swifter vehicles. The earliest known examples of these spoked designs come from the Sintashta culture around 2000 BCE at Krivoye Lake. Horse cultures in the Caucasus region soon adopted horse-drawn spoked-wheel war chariots for three centuries.
Celtic chariots introduced an iron rim around the wheel in the 1st millennium BCE. This innovation strengthened the structure against heavy use on rough terrain. In China, wheel tracks dating to around 2200 BCE have been found at Pingliangtai. Similar tracks appeared at Yanshi, a city of the Erlitou culture, around 1700 BCE. Spoked wheels arrived in Qinghai between 2000 and 1500 BCE after being imported from the west. A large wooden wheel measuring about one meter in diameter was uncovered at the Must Farm site in East Anglia in 2016. That specimen dates from 1100 to 800 BCE.
Large-scale use of wheels did not occur in the Americas prior to European contact. Numerous small wheeled artifacts identified as children's toys were found in Mexican archaeological sites. Some of these toys date to approximately 1500 BCE yet remained unused for practical transport. The primary obstacle appears to be the absence of domesticated large animals capable of pulling carriages. The American bison is difficult to domesticate and was never successfully tamed by Native Americans. Horse species existed until about 12,000 years ago but ultimately became extinct before European arrival.
The only large animal domesticated in the Western hemisphere was the llama. This pack animal was not physically suited to pull wheeled vehicles. Llama usage did not spread far beyond the Andes by the time Europeans arrived. Mesoamericans never developed the wheelbarrow or any other practical object with a wheel. Aboriginal Australians traditionally used circular discs rolled along the ground for target practice instead of transportation. Nubians from after about 400 BCE used wheels for spinning pottery and as water wheels thought to be ox-driven.
Wire-spoked wheels and pneumatic tires were invented in the 1870s. These innovations replaced earlier solid wooden designs that had been in use without major modification. Wire spokes function under tension rather than compression making it possible for the wheel to remain both stiff and light. Aeronautical engineer George Cayley invented wire wheels while James Starley first used them on bicycles. Cast alloy wheels are now more commonly used while forged alloy wheels appear when weight is critical.
Pneumatic tires consist of a doughnut-shaped body of cords and wires encased in rubber filled with compressed air. Before rubber existed, the first versions of tires were simply bands of metal fitted around wooden wheels. Modern tires contain synthetic rubber, natural rubber, fabric, and wire along with other compound chemicals. The tread provides traction while the body ensures support. Pneumatic tires are used on cars, bicycles, motorcycles, trucks, earthmovers, and aircraft today.
A wheeled vehicle requires much less work to move than simply dragging the same weight. Frictional work done occurs at the bearings rather than at the surface the vehicle traverses. In the simplest case the bearing is just a round hole through which the axle passes. Even with this plain bearing the frictional work reduces significantly because the sliding distance decreases for a given travel distance. The coefficient of friction at the interface usually remains lower than direct contact drag.
If one drags a 100 kg object for 10 meters along a surface with a friction coefficient of 0.5 the required energy equals 4905 joules. Giving that object four wheels changes the calculation entirely. With a wheel diameter of 1000 mm and an axle diameter of 50 mm the sliding surfaces only slide over each other a distance of 0.5 meters. The work done drops to 123 joules representing one-fortieth of the effort needed for dragging. Additional energy loss comes from rolling resistance which depends on ground nature and material deformation.
The wheel has become a strong cultural and spiritual metaphor for a cycle or regular repetition. The Kalachakra or wheel of time appears in some forms of Buddhism alongside the dharmachakra. Ancient China saw the wheel as a symbol of health and strength used by villages to predict future success. The diameter of the wheel served as an indicator of one's future health. In medieval Europe the Wheel of Fortune showed the transitory character of power where a person rising to the top might fall again.
The winged wheel serves as a symbol of progress seen in many contexts including the coat of arms of Panama. It appears on the flag of India representing law known as dharma. The wheel also features prominently on the flag of the Romani people hinting at their nomadic history. Some Neopagans such as Wiccans have adopted the Wheel of the Year into their religious practices. The sun cross held significance in Bronze Age religion replacing earlier concepts with more technologically advanced solar chariots.
Common questions
When was the oldest surviving wooden wheel and axle combination created?
The oldest surviving wooden wheel and axle combination dates to between 3340 and 3030 BCE. Archaeologists discovered this artifact at Stare Gmajne near Ljubljana in Slovenia, now known as the Ljubljana Marshes Wheel.
Where did early depictions of wheeled vehicles appear around 3500 BCE?
Depictions of wheeled vehicles appear on clay tablets from Uruk in Mesopotamia around 3500 to 3350 BCE. A Funnelbeaker culture settlement in southern Poland yielded a Bronocice clay pot showing a wheeled vehicle dated between 3631 and 3380 BCE.
What culture developed the earliest known spoked wheels around 2000 BCE?
The earliest known examples of these spoked designs come from the Sintashta culture around 2000 BCE at Krivoye Lake. Horse cultures in the Caucasus region soon adopted horse-drawn spoked-wheel war chariots for three centuries.
Why did large-scale use of wheels not occur in the Americas prior to European contact?
The primary obstacle appears to be the absence of domesticated large animals capable of pulling carriages. The American bison is difficult to domesticate and was never successfully tamed by Native Americans while horse species became extinct before European arrival.
Who invented wire-spoked wheels and pneumatic tires in the 1870s?
Aeronautical engineer George Cayley invented wire wheels while James Starley first used them on bicycles. Wire-spoked wheels and pneumatic tires were invented in the 1870s to replace earlier solid wooden designs that had been in use without major modification.