Wheeled

Wheeled refers to devices and systems that use wheels to enable motion by rolling rather than sliding. A wheel is a circular component that rotates around an axle, reducing friction and supporting the weight of a load. The combination of wheel and axle is a simple machine that can change the direction of force, increase speed, and improve efficiency.

Wheels first appeared in the late Neolithic period, with the earliest known examples dating to about 3500–3000 BCE in Mesopotamia. They were initially wooden disks used on carts and chariots, enabling greater transport over longer distances. Over time, wheel designs advanced to include spokes for reduced weight, rims for durability, and, later, torsion and suspension elements to improve stability.

In modern practice, wheels come in many types and are paired with tires or treads to suit terrain and load. Common wheel categories include rigid wooden or metal wheels, spoked wheels, and caster wheels for swiveling motion. Vehicle wheels are typically used with tires made of rubber or other elastomeric materials, which provide traction and cushioning. The choice of material and construction affects strength, weight, and rolling resistance.

Wheeled technology underpins most contemporary transportation, manufacturing, and logistics systems. From bicycles and cars to conveyor belts and robotic platforms, wheels enable efficient movement, precise control, and scalable load management, making them a foundational element of engineering and everyday life.