A bicycle is a human-powered, two-wheeled, pedal-driven vehicle. It has a frame with two wheels attached to a crank in front of the rider, and a chain that connects the frame-mounted cranks to the rear wheel. A bicycle can also have one or more gears, which vary the amount of power that the rider has to apply to the pedals in order to increase or decrease the speed of the bike.
The first bicycles were called ordinaries or velocipedes (a velocipede is technically the plural of ordinary, but in this context they are often simply referred to as “bikes”). They had large front wheels and were heavy, making them impractical for use on rough roads. In the 1870s, a Boston industrialist named Albert E. Pope began to import British ordinaries, and by 1880 he was manufacturing his own models, marking the start of the American bicycle industry. Ordinaries had a fixed number of speeds that were determined by the size of the front wheel and the rider’s leg length. A front wheel that was 40 to 60 inches (102 to 152 centimeters) in diameter would allow the rider to pedal at a rate of 18.5 mph (30 kph).
By the mid-1880s, safe and lightweight bicycles were being mass-produced. The most common model was a diamond-pattern, which had a rigid frame and solid rubber tires. The next improvement was pneumatic tires, which were introduced in 1888 by a Scottish veterinarian named John Boyd Dunlop. These were much more comfortable than the solid tires and allowed a higher speed.
Today, there are many different kinds of bikes for both adults and children. They can be used for recreation, fitness, transportation, and racing. Some people even use them to carry loads. Bicycles are used as a means of public transportation in many cities.
The bicycle is the most efficient means yet devised for converting human energy into mobility. The bicycle’s design is simple enough for almost anyone to understand and repair, though some maintenance is required on a regular basis. The International Organization for Standardization has a special technical committee, TC149, which establishes standards for cycles and their components and accessories.
Cycling is a great way to get exercise and stay healthy. It strengthens the legs, arms, and core muscles. It can also help people lose weight and lower blood pressure. It is also an environmentally friendly mode of transportation. It eliminates the need for gasoline-powered cars, which produce harmful pollutants. It also reduces traffic congestion and noise pollution, which can be disruptive to our health. In addition, it eliminates the need to use fossil fuels, which contribute to global warming. It is a fun and enjoyable activity that everyone should try. It is also important to remember that cycling requires safety skills. This is especially true when riding on busy streets. Always wear a helmet and follow the rules of the road. For example, a cyclist should always stop at red lights and signals when changing lanes.