A bicycle, also known as a push bike or cycle, is a human-powered, two-wheeled, pedal-driven vehicle that allows people to move quickly and easily. A person who rides a bicycle is called a cyclist, and the word “bike” is derived from the French term for “wheel.” The first bicycles were invented in the 19th century. There are now more than 1 billion bicycles worldwide. Bicycles are used for recreation, exercise, transportation, and racing. They are also often modified with pegs or other attachments for stunts, military and police applications, courier services, and artistic cycling.

The first bicycles were heavy and cumbersome, and were often referred to as hobby horses or velocipedes. Inventors struggled with ways to make them lighter and more user-friendly, and the modern bicycle was born. It is unclear who first conceived the idea of attaching pedals directly to the front wheel of a bicycle, but it was around the early 1860s that these improvements began appearing on the market.

The earliest bikes had wooden frames, which were strong but heavy and difficult to repair. Metal frames were introduced in the 1880s, and they were much easier to maintain. James Kemp Starley, a former bicycle mechanic in northern England, is generally credited with developing the first practical steel bicycle in 1885. Starley’s invention revolutionized transportation, and his bicycle company went on to manufacture motorcycles and later cars.

In the late 1800s, the bicycle became extremely popular in Europe and the United States, as ordinary people took to the roads on their new steeds. Even royalty took up the sport, with the sultan of Zanzibar purchasing bicycles for his entire harem. With a bicycle, anyone could travel far and fast, and the world seemed like an endless playground.

Riding a bike is an incredibly efficient way to get around, and it requires relatively little maintenance. A good bicycle will last for decades with proper care. Its basic parts include a frame, tires, wheels, and handlebars. The frame is a long tube, usually made of steel, that supports the rider and provides the mounting point for the pedals. The wheels are made of spokes, which are thin metal rings that connect the rim to the hub. The rim is then covered with rubber to make the wheel smooth and reduce friction (the rubbing force between two objects). The wheels are held in place by high-tension wires that run from the hub to the axle.

There is no such thing as a completely rigid frame, so even the strongest of materials will give a bit under certain kinds of force at different times and under the weight of a rider who is of different heights and shapes. The flexing of the frame, which is most noticeable when riding up and down hills, helps a bike to absorb shocks and offer greater control and comfort to its rider. The spokes of the wheel are also tensioned, to help cut drag (the friction caused by air resistance). This is why most modern bicycles have a front and rear derailleur system that uses shift levers to select from one of several gears, allowing a rider to vary their speed or power output without having to stop.