Cycling is the sport, recreational activity and means of transportation of riding a bicycle. Since the creation of the first practical bicycles in the early 1800s, cycling has grown to the point that each year roughly 100 million bicycles are produced worldwide.
There are three main branches to the sport of cycle racing: track cycling, road racing, and off-road racing. They differ in the types of racing involved, the nature of the race courses, and in the equipment used.
Track cycling was one of the earliest forms of cycle racing. In the 1890s and the first decades of the 20th century, it was extremely popular both in the United States and in Europe.
This form of racing takes place in a special type of stadium known as a velodrome. The velodrome can be constructed either indoors or outdoors. It consists of an oval circuit up to 1/4 of a mile in length with either a concrete or wooden surface.
The bicycle used in track cycling is a specially stripped down, lightweight version of a regular bicycle in that it has no brakes and uses a fixed gear.
Road cycling is called thusly because it normally takes place on ordinary surface roads or streets. Within the rubric of road cycle racing there are several forms: time trials, stage races, circuit races and criteriums.
The stage race is perhaps the most well-known form of road cycle racing, having gained widespread popularity and recognition through races such as the Tour de France. The stage race can include time trials. It is a team sport in that the racers are part of a team of riders whose main objective is to assist their team leader in posting the lowest elapsed time for the duration of the race.
This aspect of the sport of cycle racing typically takes place on unpaved courses. The team aspect of the actual racing is considerably lessened by comparison to road cycle racing due to the narrow course paths. There are several forms, including mountain bike racing, BMX racing, and cyclo-cross. One aspect which markedly differentiates these types of racing competitions from road racing is the bike, which in these off-road races will typically exhibit wider tires, often with some knobbiness or tread on the wheels to improve traction.
The governing body for the sport of cycle racing worldwide is the Union Cycliste Internationale (UCI). It is one of the International Federations of the International Olympic Committee (IOC) and is, in turn, composed of member national federations, such as USA Cycling (USAC) in the United States.