It's pouring down rain, the wind is cold, and the racetrack is full of mud, ruts, rocks and barriers. The contestants are soaked to the skin, their brightly colored cycling apparel is dulled with smears of mud, and their faces look like they have been bobbing for apples in a mud pie. They seem to carry their bikes on their shoulders more than they ride them. According to other cyclists, these folks are a bit deranged and have more than a few screws loose.

It's pouring down rain, the wind is cold, and the racetrack is full of mud, ruts, rocks and barriers. The contestants are soaked to the skin, their brightly colored cycling apparel is dulled with smears of mud, and their faces look like they have been bobbing for apples in a mud pie. They seem to carry their bikes on their shoulders more than they ride them. According to other cyclists, these folks are a bit deranged and have more than a few screws loose.

Welcome to the world of cyclocross, a form of bicycle racing normally held during the fall and winter months. Cyclocross events occur on short courses (one to two miles) that traverse pavement, wooded trails, grass, steep hills and obstacles that require the rider to dismount, carry the bike over the obstruction and remount (sometimes quickly and gracefully, sometimes not).

The sport has been strongest in the traditional road cycling countries of Europe. However, cyclocross became popular in the United States in the 1970s, and in 1975 the first U.S. National Championship was held in Berkeley, Calif. The sport has experienced a growth in popularity in the U.S. since the mid-'90s, and now Portland hosts some of the largest cyclocross events in the country.

Numerous stories exist about how this twist in bicycle racing got started.

Most people agree it began during the early 1900s when European bicycle racers tried to stay in shape during the winter months by racing each other from one town to the next. Sometimes the faster route to the next town was a cross-country shortcut, riding across farmer's fields, hopping fences, and dodging farm animals. These spontaneous events improved the cyclists' road-handling skills and overall fitness, because riding off-road is more difficult than cruising on pavement. Daniel Gousseau of France is credited as having inspired the first cyclocross races and organizing the first French National Championship in 1902.

Races consist of many laps over a short course, ending when a time limit is reached rather than after a specific number of laps or certain distance. Depending on the skill level of the riders, races usually last from 30 minutes to an hour. A race event schedule would read 50 minutes plus one lap. Generally each lap is one to two miles long and 90 percent rideable. The racetrack can vary from single track-width to 10 feet wide to allow passing opportunities.

Cyclocross bicycles resemble road racing bicycles in being lightweight, with narrow tires and drop handlebars. However, they also share characteristics with mountain bicycles in that they utilize knobby tread tires for traction, and cantilever-style brakes for clearance needed in muddy conditions. The bicycles must be lightweight for competitors to carry them over barriers or up slopes too steep to climb in the saddle. Newer mountain bikes are lightweight, so don't be surprised to see mountain bikes at local competitions.

In most races, cyclocross riders are allowed to change bicycles and receive mechanical assistance during the race. While the rider is on the course getting one bike dirty, the pit crew can work quickly to clean, repair and lubricate a spare. Having a mechanic in the "pits" is more common for professional cyclocross racers. The average cyclocross racer might have a family member or friend holding their spare bike, if they are fortunate enough to own two.

The clothing worn by cyclocross riders is similar to that of road-racing participants. However, since cyclocross is a cold-weather sport, riders lean toward warmer clothing, such as long-fingered gloves, long sleeves, tights, mountain biking shorts and arm and leg warmers.

In areas with warmer climates, racers prefer skinsuits, which maximize freedom of movement while preventing the jersey from getting caught on stray tree branches or other obstacles. Mountain bike shoes are preferred, as they provide better traction than road shoes. Toe studs are occasionally used to aid in running up steep, muddy slopes.

Unlike road-racing events, where the cyclists whiz by in seconds, never to be seen again, cyclocross is a good spectator sport. One can usually see most of the course, lap circuits are fairly close and all the action can be easily viewed by walking around the outside of the course.

If you appreciate skilled bike riding and want to see an action-packed event, grab your all-weather clothing and head to a cyclocross event. A local competition, the Outlaw Cyclocross Race Series, is being staged at Greenhorn Park in Yreka, Tom Pearce Park in Grants Pass and Emigrant Lake near Ashland. See the article in this Outdoors section for dates and race times. Other cyclocross events in Oregon can be found at www.obra.org, www.mtbzone.com/nwcross.html, and www.orbike.com.

Bicycling enthusiast Bob Korfhage of Phoenix is a former president of Siskiyou Velo bicycle club.