A bicycle is a human-powered, two-wheeled vehicle with pedals for the rider to push. The bicycle is the most popular means of transport in the world and outsells automobiles by a factor of three to one. It is used for recreation, fitness, transportation, and competition. The bicycle’s design has evolved over time; however, the basic form remains constant. The modern bicycle is typically constructed from a steel frame with aluminum or carbon fiber components. A bicycle’s drivetrain is composed of the pedals, cranks, chain, and rear wheel. The chain is a linkage that connects the pedals and the cranks. Depending on the model of the bicycle, it may also have a shaft drive, special belts, or hydraulic transmission.

The bicycle’s history has been closely linked to the development of mankind and technology. Throughout the years, it has become an important mode of transportation for both the rich and the poor, and it is considered a great means of exercise. Historians disagree on who invented the first bicycle, with Leonardo da Vinci credited with a sketch of one in his Codex Atlanticus of 1492, but it is generally accepted that the bicycle has been around for over 200 years.

In the early 1800s, inventors made significant improvements to make bicycles more comfortable and efficient. The draisine, which had solid iron wheels without tires, was replaced by the bicycle with a pneumatic tire. These bicycles, which were called boneshakers in the United States, were uncomfortable and dangerous to ride. Improvements included a freewheel, which allowed the bike to spin even when the rider wasn’t pedaling, and better hand brakes.

Bicycles are now more common and safer to ride than ever before. They have become a mainstay of local transportation systems in many countries and are commonly used in urban areas for commuting, shopping, and other day-to-day activities. They are also used for sports, leisure, and work, including delivery services, police and military applications, and racing.

Preparation is key to safe cycling, whether on the road or off. Educating yourself on the rules of the road and understanding your bike’s riding characteristics will help to ensure that you have a pleasant and safe experience.

Bicyclists should take advantage of public education programs to increase their cycling skills and knowledge. They should also familiarize themselves with the laws in their area before riding a bicycle on roads that are not designed for them or when they share the road with motorists. Bicyclists should practice riding in a safe and convenient location before attempting to navigate traffic-filled streets or bike trails. Finally, cyclists should take steps to protect themselves from injury by wearing a helmet and clothing appropriate for their climate and environment. They should also carry identification in case they are injured or separated from their bicycle. This can be done by keeping a copy of their driver’s license on them at all times, and by carrying a copy of a medical certificate in case they are hurt.