The huge increase in mountain bike popularity over the past decade has predictably led to the rise of mountain bike racing. From its roots in cyclocross and BMX racing, mountain biking has blossomed to become a major form of racing. Just recently, it reached new international acceptance by becoming an official event in the 1996 Olympics.

The National Off-Road Bicycle Association (NORBA), which is affiliated with the USCF, is the governing body of professional and amateur mountain bike racing in the United States. Like other types of bike racing, riders can compete in a number of different events.

Cyclocross

Because cyclocross race courses can be partially (though no more than half) paved, and also because cyclocross developed as a wintertime diversion of road racers, the USCF categorizes it as a road race. However, cyclocross racing is generally done off-road and is therefore the predecessor to the newer sport of mountain bike racing. Cyclocross courses even include terrain too rough to navigate on bike at all, requiring riders to carry their bikes.

Cyclocross is a mass-start race usually held on a large circuit with natural obstacles. Cyclocross bikes are neither as heavy nor as rugged as mountain bikes, and their tires are thinner as well. While the growth of mountain bike racing has made cyclocross somewhat redundant in the United States, it remains popular in European off-road competition. Cyclocross races tend to run 20 kilometers long for amateurs and 35 kilometers long for professionals.

Bicycle Motocross (BMX)

BMX bikes were first popularized in the 1960s as a nonmotorized kids’ version of motocross motorcycles. Since then, the BMX bike has been a hugely popular kids’ bike. Whether or not kids actually race, quite often some sort of BMX-style bike is the first bike they get.

BMX racing boomed in the 1970s and continues to be very popular today for kids between five and seventeen (with professionals continuing into adulthood). Over one hundred BMX race tracks across the country host races year-round. BMX racing heats, called motos, take place on dirt tracks and run anywhere from 400 to 1,000 meters long. Racers start the race on a short downhill ramp to build up speed, and may encounter gravel, water obstacles, and jumps throughout the race.

Cross-Country Races

Cross-country races are essentially the same as cyclocross, except that for cross-country racing the traditional racing-style cyclocross bike is replaced by a mountain bike, and courses are shorter. Like cyclocross, cross-country racing is done on a circuit track with a variety of terrains, including trails, fields, or gravel roads. It may also be point-to-point if the course is suitably rough. Because a part of the track may be paved, cross-country somewhat overlaps the worlds of off-road and road racing.

Downhill and Uphill Races

Somewhat similar to skiing, downhill mountain biking is an individual time trial that takes place on steep, high-speed descents (often at ski resorts). Like other time trials, riders typically begin at regular intervals and race against the clock. Uphill races, though much less popular than downhill races (for obvious reasons), can be timed or mass-start.

Dual Slalom Races

Also based on a skiing event, dual slalom races pit two riders against each other on a downhill race through a slalom course. Racers must zig-zag around a series of gates, with time penalties for missed gates. In competition, dual slalom heats are part of an elimination tournament, where the winners advance to the next round until an overall winner is determined.

Observed Trials

This is not so much a race as a performance. Riders follow an obstacle course, 25 to 100 feet long and often divided into separate sections, that contains natural hazards such as rocks, logs, mounds, streams, and mud. Using bike handling skills, the riders attempt to complete the course in a prescribed period of time without setting foot (or hand) on the ground. Each time the rider's body touches the ground—called a dab—the rider gets one or more points, depending on the severity and the number of previous dabs. The rider with the least amount of points at the end is the winner.

Stage Races

Like road racing, mountain biking also has stage races. These may include a number of different events or they may be one long race broken up into sections. Either way, mountain stage racing tests all the skills of mountain biking, including downhill riding, hill climbing, and cross-country handling. The competition takes place over the course of one or more days, with the winner determined either by the lowest total time or the most overall points.

Ultra Endurance Races

This is the general name for any mountain biking race, usually cross-country or stage, that is more than 75 miles long. They include the Race Across America (RAAM) and the Iditabike, a race across Alaska.