kerékpárt

Kerékpárt, commonly known as a bicycle, is a human-powered or motor-powered assisted vehicle. It typically consists of two wheels attached to a frame, one behind the other. The rider propels the bicycle by pedaling, which turns a crankset connected to the rear wheel via a chain. Early bicycles, developed in the early 19th century, lacked pedals and were propelled by the rider pushing their feet against the ground. These were known as velocipedes or "boneshakers."

The development of the safety bicycle in the late 19th century, with its two wheels of equal size, chain drive, and pneumatic tires, revolutionized personal transportation. This design, with minor modifications, remains the standard for most bicycles today. Bicycles are used for a wide range of purposes, including transportation, recreation, exercise, and sport. They are an environmentally friendly mode of transport, producing no emissions and requiring minimal energy for manufacturing compared to motor vehicles.

Bicycles come in many forms, each designed for specific uses. Road bicycles are lightweight with narrow tires for speed on paved surfaces. Mountain bikes have wider tires, suspension, and robust frames for off-road terrain. Hybrid bikes combine features of both road and mountain bikes, offering versatility. BMX bikes are designed for stunts and racing. Electric bicycles, or e-bikes, incorporate an electric motor to assist pedaling, making them accessible to a wider range of riders. The bicycle is a globally significant invention that continues to play a vital role in many societies.