Professional racing originated in Western Europe, centred in France, Spain, Italy and the Low Countries.

As well as the UCI's annual World Championships for men and women, the biggest event is the Tour de France, a three-week race that can attract over 500,000 roadside supporters a day.

[4] Historically, the most competitive and devoted countries since the beginning of 20th century were Belgium, France and Italy, then road cycling spread in Colombia, Denmark, Germany, Luxembourg, the Netherlands, Portugal, Spain and Switzerland after World War II.

Individual time trial (ITT) is an event in which cyclists race alone against the clock on flat or rolling terrain, or up a mountain road.

The competitor with the lowest cumulative time to complete all stages is declared the overall, or general classification (GC), winner.

The related activity of randonneuring is not strictly a form of racing, but involves cycling a pre-determined course within a specified time limit.

Bicycle helmets were made mandatory for professional road racing in 2003, after the death of cyclist Andrey Kivilev.

This can be used as a strength or a weakness by competitors; riders can cooperate and draft each other to ride at high speed (a paceline or echelon), or one rider can sit on a competitor's wheel, forcing the other person to do a greater share of the work in maintaining the pace and to potentially tire earlier.

Working together smoothly and efficiently, a small group can potentially maintain a higher speed than the peloton, in which the remaining riders may not be as motivated or organized to chase effectively.

If the break does not succeed and the body of cyclists comes back together, a sprinter will often win by overpowering competitors in the final stretch.

[13] Teamwork between riders, both pre-arranged and ad hoc, is important in many aspects: in preventing or helping a successful break, and sometimes in delivering a sprinter to the front of the field.

In addition, because the bunch riders are keeping more space between them for safety reasons, their drafting benefits are again reduced.

If this action takes place relatively close to the target (e.g. another bunch ahead, or the finish), the ride over flatter terrain after the descent is not long enough to let the drafting effect (which is then working at full power again) make the bunch catch up, making a climb escape even more attractive.

[15] To take advantage of this, an attacking rider rides at high speed at the front of the peloton, on the opposite side of the road from which the crosswind is blowing.

While the principle remains that the winner is the first to cross the line, many riders are grouped together in teams, usually with commercial sponsors.

The other riders on the team, or domestiques, will devote themselves to promoting the leader's chances, taking turns in the wind for him, refusing to chase with the peloton when he or she escapes, and so on.

For instance, in the 2012 London Olympics men's road race the outright favourite was sprinter Mark Cavendish riding for the team of Great Britain.

[19] In September 2009, the Union Cycliste Internationale (UCI), the governing body of pro cycling, voted to phase in a ban on the use of team radios in men's elite road racing.

Riders, who finish in the stage ranking behind the general leader, increase their cumulative time disadvantage.

The former UCI Road World Cup one-day classic cycle races – which include all five "Monuments" – were also part of the ProTour: Milan–San Remo (Italy), Tour of Flanders (Belgium), Paris–Roubaix (France), Liège–Bastogne–Liège (Belgium) and Amstel Gold Race (Netherlands) in the spring, and Clásica de San Sebastián (Spain), HEW Cyclassics (Germany), Züri-Metzgete (Switzerland, until 2006), Paris–Tours (France, until 2007) and Giro di Lombardia (Italy) in the autumn season.

[24] Law enforcement always escort the athletes to ensure they are kept safe during the cycling events, especially the road races.

It was the world's first long-distance road race and also won by Moore, who took 10 hours and 25 minutes to cover 134 km.

The runners-up were the Count André Castéra, who had come second to Moore at St-Cloud, and Jean Bobillier, riding a farm bike that weighed 35 kg.

The increase in organised cycle racing led to the development of national administrative bodies, in Great Britain in 1878, France 1881, the Netherlands 1883, Germany 1884 and Sweden 1900.

Sometimes, as in Great Britain, cycling was originally administered as part of athletics, since cyclists often used the tracks used by runners.

The Bicycle Union [of Britain], having quarrelled with the Amateur Athletic Association over cycle race jurisdiction on AAA premises, took issue with the Union Vélocipèdique de France over the French body's willingness to allow its "amateurs" to compete for prizes of up to 2,000 francs, the equivalent of about sixteen months' pay for a French manual worker.

A new organisation, the Union Cycliste Internationale (UCI), was set up on 15 April 1900 during the Olympic Games in Paris, by several European countries and the United States.

In its home in Europe and in the United States, cycle racing on the road is a summer sport, although the season can start in early spring and end in autumn.

Unlike other classics, the World Championships is held on a different course each year and ridden by national rather than sponsored teams.