A bicycle is a two-wheel human-powered vehicle that you ride by sitting on it and pushing pedals with your feet while turning a bar to steer the front wheel. It also has a saddle seat or seats, gearing, and a frame. The most basic bicycles have a single-track, but some have multiple tracks or even a suspension system. Bicycles are usually called bikes, although some people refer to three-wheeled and unicycles as bikes, too.

The word “bicycle” is derived from the Latin name for the wheel, biel, and the Greek word for motion, kuklos, meaning “smooth” or “even.” This smoothness relates to the way a bicycle rides over rough surfaces, which allows a person to travel long distances in relatively short periods of time.

Many people enjoy the sport of cycling for recreational reasons. It provides an excellent cardiovascular workout and increases leg strength, balance, and flexibility. It is also a great form of low-impact exercise that doesn’t put strain on joints. Bicycling is known to help reduce the risk of heart disease, obesity, high blood pressure, depression, and stroke.

Some people use a bicycle for transportation, avoiding the expense of car insurance and the hassle of finding a parking spot in crowded areas. Bicycling can also reduce a person’s environmental footprint, as it doesn’t produce any emissions.

Thousands of people are injured or killed each year in bicycle accidents, but careful riding can greatly reduce these numbers. Educating oneself on the rules of the road is essential, as is familiarizing oneself with the safety features and riding characteristics of the bike one intends to use. Bicycle riders should also understand that they are considered vehicles from the standpoint of traffic engineering and law enforcement, and they can be ticketed for violating road rules just as drivers can be.

There are a variety of bicycles available, ranging from mountain bikes and racing models to family cruisers and touring bikes. In addition, there are numerous accessories and parts for the bike, such as fenders, lights, racks, and a wide range of tires. Some of these items are optional, but others are essential for safe and comfortable cycling.

Road bikes are designed to be efficient on road, and they tend to have handlebars with a narrow diameter, so a rider can crouch while riding to minimize wind resistance. Triathlon and time trial bicycles are specially designed for speed, with a frame that allows the rider to lean forward as much as possible, and handlebars with special aerodynamic grips. Bicyclists who compete in races often have special clothing, including aerodynamic helmets and suits, to improve their chances of winning.