Cyclo-cross (cyclocross, CX, cyclo-X or cross) is a form of bicycle racing. Races typically take place in the autumn and winter (the international or "World Cup" season is October–February), and consist of many laps of a short (2.5–3.5 km or 1.5–2 mile) course featuring pavement, wooded trails, grass, steep hills and obstacles requiring the rider to quickly dismount, carry the bike while navigating the obstruction and remount.uci.ch UCI Cyclo-cross regulationsusacycling.org USA Cycling Federation rulebook Races for senior categories are generally between 40 minutes and an hour long, with the distance varying depending on the ground conditions. The sport is strongest in the traditional road cycling countries such as Belgium (Flanders in particular), France and the Netherlands.

Cyclo-cross has parallels with mountain bike racing, cross-country cycling and criterium racing. Many of the best cyclo-cross riders cross train in other cycling disciplines; however, cyclo-cross has reached such size and popularity that some racers are specialists, and many prioritize cyclo-cross races over other disciplines. Cyclo-cross bicycles are similar to road racing bicycles: lightweight, with somewhat narrow tires and drop handlebars. They are typically differentiated by their greater tire clearances, lower gearing, stronger frames, cantilever brakes or disc brakes and more upright riding position. They also share characteristics with mountain bikes in that they use knobby tread tires for traction and disc brakes. They have to be lightweight because competitors need to carry their bicycle to overcome barriers or slopes too steep to climb in the saddle. The sight of competitors struggling up a muddy slope with bicycles on their shoulders is the classic image of the sport, although unridable sections are generally a very small fraction of the race distance.

Compared with many disciplines of road and track cycle racing, tactics are fairly straightforward, and the emphasis is on the rider's aerobic endurance and bike-handling skills. Drafting, where cyclists form a line with the lead cyclist pedaling harder while reducing the wind resistance for other riders, is of much less importance than in road racing where average speeds are much higher than in cyclo-cross.

A cyclo-cross rider is allowed to change bicycles and receive mechanical assistance during a race. While the rider is on the course on one bike, their pit crew can clean, repair and oil a spare.

Origins and history

There are many stories about the origins of cyclo-cross. One is that European road racers in the early 1900s would race each other to the next town over from them and that they were allowed to cut through farmers' fields or over fences, or take any other shortcuts, in order to make it to the next town first. This was sometimes called steeple chase as the only visible landmark in the next town was often the steeple. This was a way for them to stay in shape during the winter months and put a twist on road racing. In addition, riding off-road in more difficult conditions than smooth pavement increased the intensity at which the cyclists were riding and improved their on-the-road bike handling abilities. Forced running sections, or portage, were incorporated to help deliver warm blood to the feet and toes, as well as exercise other groups of muscles. Daniel Gousseau of France is credited as having inspired the first cyclo-cross races and organized the first French National Championship in 1902.Cyclocross: History & What You Should Know Konrad, Gabe: "Cyclocross: History & What You Should Know". Bicycle Trader Magazine, 1996. Retrieved 15 May 2012. Géo Lefèvre, the originator of the idea for the Tour de France, also played a key role in the early days of the sport.cyclingnews.com, "Who got their tyres crossed?", 9 November 2006

After Octave Lapize attributed his win in the 1910 Tour de France to his off season training in cyclo-cross books.google.com Herlihy, David V. "Bicycle: The History", page 397. Yale University Press, 2004. the sport began to spread to countries bordering France. Belgium organized its first national championship in 1910, Switzerland did so in 1912, then Luxembourg in 1923, Spain in 1929 and Italy in 1930.

Cyclo-cross proved itself as a sport extending beyond the boundaries of France when in 1924 the first international race, Le Critérium International de Cross-Country Cyclo-Pédestre, was held in Paris.

Like many international cycle sports, cyclo-cross is administered by the Union Cycliste Internationale; although it was not until the 1940s, around 40 years after cyclo-cross' inception, that the UCI began its regulation and the first world championship was held in Paris in 1950.

The first United States Cyclo-cross National Championships took place on 20 October 1963, in Palos Park, IL, near Chicago.cvccbike.com Schwartz, Bob. The 1963 US Cyclocross National Championships. These championships in the midwest continued until 1969. Cyclo-cross began to become popular in the United States in the 1970s, in New England and California. The Cyclo-cross National Championships restarted in 1975 in Berkeley, CA and have continued to be held every year at various locations throughout the United States. The Surf City race series held in Santa Cruz, CA has contributed to the history of cyclo-cross in the United States. The sport has experienced a growth in popularity in the United States since the mid-1990s.books.google.com Burke, Edmund R. & Pavelka, Ed: "The Complete Book of Long Distance Cycling", Page 254. Rodale, 2000. Cyclo-cross races are now regularly held in the fall and winter seasons throughout the United States and continue to grow in popularity.

Racing seasons Cyclocross is typically an autumn and winter sport, the northern hemisphere season running from September to February. The World Championships take place in late January. The Canada championships are held in November with the US and UK championships held in January. In the United States, there is little racing after that except in states with year-round warm climates such as Florida and California. The cyclocross racing season within southern hemisphere nations typically runs from May to August.

Riders' age categories for cyclocross under UCI rules are currently determined by their age on 1 January which lies in the middle of the international season, i.e. they compete in the same category that they would be in for the following road season.

Equipment

Bicycles

Cyclo-cross bicycles generally resemble road racing bicycles. Cyclo-cross-specific frames differ with their wider tire clearances, knobby tires, cantilever or disc brakes, and lower gearing. Cables are generally routed on the upper side of the top tube, which allows the rider to carry the bike comfortably on the right shoulder through portage sections, and prevents cable contamination by dirt. Popular on many cyclocross bikes is routing the brakes so that the right brake is often the front brake. This is done to allow the left hand to control speed while approaching obstacles requiring the bike to be carried, while the right hand grips the frame ready to lift the bike onto the shoulder as soon as the rider's feet touch the ground. As a high-end bicycle purpose-built for a specific sport competition, they also differ from ordinary "hybrid or trekking" cross bikes, which are general-purpose utility bikes fitted with slightly wider 700C tires for use on unpaved paths or trails.Ballantine, Richard, Richard's 21st Century Bicycle Book, New York: Overlook Press (2001), , pp. 34, 307

Cyclo-cross bike design and frame geometry has evolved over the years. The first cyclo-cross bikes were touring-type road bikes, used for their cantilever bosses, slacker angles and wider tire clearance. Over time as the sport became more formalized, frame angles changed for quicker handling and bottom brackets heights were raised to clear broken ground. Most cyclo-cross frames have a non-compact (flat or near-flat top tube) frame design for easier shouldering. Some design features have recently begun to change, for example, a heightened bottom bracket was typical 10+ years ago; now many cyclo-cross-specific frames do not have elevated bottom brackets, in fact many have a lower bottom bracket than road racing bicycles; this is favorable since the lower seat height makes for easier remounting, and a lower center of gravity increases stability. Many cyclo-cross bicycles are now set up with a single chainring and chain "drop" guards. A single chainring setup simplifies mechanics and reduces the chance of the chain derailing on a bumpy course. People who do run a double chain-ring set up on their bicycles generally use a 36–46 gearing. Many professional-level cyclo-cross bikes are set up with deep-section carbon tubular wheels, not for the purpose of aerodynamics, but to keep the wheel from being entrapped in deep sand or mud sections. Tubular tires are used to avoid pinch flats, decrease rolling resistance and increase grip with lower tire pressures. In addition, single speed cyclo-cross bikes are becoming increasingly popular for a variety of reasons, including lower initial cost of setup, ease of use and maintenance, and decreased likelihood of mechanical failure on the course.

Clothing

Clothing is similar to that of road racing. However, since cyclo-cross is a cold-weather sport there is an emphasis toward warmer clothing such as long sleeves, tights, knickers and arm and leg warmers. While many racers will use standard two-piece road kits, there is a very strong preference to wear one piece skinsuits to maximize freedom of movement. The other advantage of skinsuits is that they are tighter, preventing the jersey from getting caught on stray tree branches during some singletrack sections of the race course. The one piece construction of the skinsuit also prevents it from exposing the torso while the rider shoulders the bike. Mountain bike shoes are adopted, as they allow the competitors to run, unlike their road racing counterparts, and due to their degree of traction (compared to smooth bottoms found on road racing shoes). Toe spikes are used to aid in running up steep muddy slopes and in the adverse underfoot conditions. Full-finger gloves are optional but generally recommended for hand protection and for grip in muddy/wet situations. Experienced riders racing in dry conditions may eschew gloves, presumably for better tractional feedback though the handlebar, and more natural bike portage.

Courses