The bicycle is a human-powered vehicle with two wheels attached to a frame that’s steered with handlebars. Also known as a bike, pedal cycle, or velocipede, it’s considered the most efficient means of human-powered transportation available. It can be used for recreation, transportation, or as a form of exercise. Some people use it as a means of commuter transportation. Others participate in cycling events and races. There are more than 1 billion bicycles in the world.

Leonardo da Vinci sketched a precursor to the modern bicycle in 1492. Inventors in the 19th century developed different designs, including a chain-driven bicycle that could reach speeds of up to 30 miles per hour. Today’s bicycles are made from a variety of materials, and they have a wide range of features that allow them to be used for different purposes. The most important parts of a bicycle are its frame, wheels, and drivetrain. The drivetrain consists of a crank on the right side of the bicycle, with a set of gears that rotate the crank when the cyclist pedals. The crank connects to a chain that runs around the frame and transfers power from the pedals to the rear wheel. The chain is also connected to a derailleur, which shifts the chain into different gears as the rider pedals.

Some bicycles have coaster brakes, which work by letting the rider push backward on the pedals to stop the vehicle. Other bicycles have hand brakes, which work when the rider squeezes levers on the handlebars. The pads on the brakes contact the wheels and generate friction that slows the bicycle down.

There are many different kinds of bicycles, each designed for a specific purpose or type of terrain. Road bikes are built for fast riding on paved roads. Mountain bikes are designed for off-road riding, with rugged tires and specialized components that can withstand rough terrain. Bicycles can be adapted for a variety of uses, from cruising to hauling cargo.

Choosing the right bicycle requires some research. The best way to learn about the various types of bikes is to read cycling magazines and blogs. Bike reviews can be helpful, but it’s important to remember that a review is only one person’s opinion. Many bike-reviewers have their own “bike-love story,” and they are usually biased toward the bikes they like. Some readers may be tempted to believe that the bike they read about is their new best friend, but it takes years to get to know a bicycle well enough to judge its strengths and weaknesses.

In addition to reading bike reviews, it’s also a good idea to seek out people who do the sort of riding you enjoy and try their bikes. Bike media can be like a bag of Kirkland trail mix, with plenty of sugary and unhealthy stuff. Learning from people who live and breathe biking can help you find the healthy bits.