A bicycle is a two-wheeled vehicle with pedals for propulsion. It is usually designed for riding on paved roads and paths. It is also used in racing and other competitive sports. Bicycles are relatively simple machines compared to motor vehicles and have many moving parts that can wear out. Regular maintenance and replacement of worn components is required to keep a bicycle in good working order. Some cyclists choose to do some of the work themselves, especially when they have a basic understanding of how their bike works.

There are many different types of bicycles. The type you choose should be based on your intended use, the terrain where you will ride, whether you will carry cargo or children, and your fitness level. Bicycles come in a wide range of prices, from low-cost utilitarian models to high-end racers.

The first practical bicycles were developed in the late 1860s. These were based on German inventor Karl Drais’s velocipede, which had a platform for the rider that was raised above the ground by cranks attached to the wheel. Drais’s design had one major flaw: it was difficult to maintain balance with the platform lowered below the seat.

To solve this problem, Englishman John Kemp Starley designed a bicycle with equal-sized wheels and a shorter platform in 1885. This design, which he called the safety bicycle, was a great success and led to the bicycle boom of the 1890s. During this time, cycling moved from being a sport and hobby to a form of basic transportation for people of all classes, races, and sexes.

Modern bicycles are designed to carry the rider comfortably while converting most of the energy from the rider’s movement into kinetic energy that moves the bicycle forward. To achieve this, the frame of a modern bicycle is constructed from lightweight materials, such as aluminum or steel. These materials are shaped to provide the frame with its strength, rigidity, and responsiveness. In addition, the seat is designed to allow the rider to sit in a comfortable upright position. Some seats even have longitudinal slots to avoid perineal pressure and saddle sores.

There are many things to consider when selecting a new bicycle, including your height, weight, and fitness level. To ensure a safe ride, it is important that your bicycle fit you properly. To check this, look for a frame size label on the bottom bracket and a measurement chart in the owner’s manual. These charts give you the reach and stack measurements of the frame, which should be close to your body measurements. You can also find other useful information in the owner’s manual, such as tips for riding safely and a list of recommended accessories. To reduce the risk of injury, it is essential that you use a helmet whenever you are riding your bicycle. You should also be familiar with local road rules and traffic laws.