China's first-ever Olympic summer games also marks the first time bicycle motocross (BMX) athletes can go for the gold in the world's most prestigious athletic event. Forty-eight BMX cyclists—including four Americans—will bring the sport from its humble dirt track origins in Orange County, Calif., all the way to the Laoshan Mountain track in Beijing.

BMX racing is different from other Olympic cycling events in several key ways: the races last less than a minute, the bikes are small and low to the ground, and the racers must wear protective gear over their faces, heads and joints to protect against likely collisions. It introduces an element of "extreme sports" to the summer games expected to appeal to younger viewers, much the way snowboarding did when it debuted in 1998 at the Nagano, Japan, Winter Olympics, according to Bob Tedesco, managing director of the National Bicycle League in Hilliard, Ohio.

The sport's long road to Beijing began in 1974 when George Esser founded the National Bicycle League as a nonprofit bicycle motocross sanctioning organization. The first world BMX championships were held in the early 1980s. It wasn't until 2003 that the International Olympic Committee (IOC) decided that BMX would be an official sport in the 2008 Games. "BMX became an Olympic sport primarily because of the exposure it got on television as part of the ESPN X Games," says Jay Townley, a cycling industry consultant in Lyndon Station, Wisc.

Unlike the Olympic road and mountain bike races, which take place over dozens of miles and last several hours, a BMX race is a sprint. Not a sprint on a super-smooth track such as the one used for the track cycling competition, but a mad dash across a course that is about 1,148 feet (350 meters) long and 32 feet (10 meters) wide, with three-hairpin turns and four jump-filled straight-aways.

A BMX racer begins with a standing start and accelerates through the finish line. Riders charge side-by-side down a 26-foot (eight-meter) ramp, angled at a 28-degree slope, to build speed and acceleration of up to 40 miles per hour within the first six seconds of the race. "Standing up works for acceleration and maneuverability," says Robert Kahler, senior product manager for GT Bicycles in Madison, Wisc. "You have a very low height to the frame so you can get … over the jumps as efficiently as possible."

BMX bikes use a single gear throughout the race. Riders use only a rear-wheel brake that is used mostly to avoid riders who have crashed on the course and to stop after crossing the finish line—other types of cycles have a two-brake system that slows both wheels.

Despite being the world’s largest producer of bicycles (59 million units built in 2007) and having the most riders (28 million bikes sold in 2007), according to Bicycle Retailer and Industry News, China will not get a crack at winning the Olympics' first BMX gold medal. The country, which has had a national BMX team since 2003 and won the Asian Championships that year, failed to qualify for the Games.

But China hopes to win the country's first cycling gold medal in the women's mountain bike race. Team members Ren Chengyuan, 21, and Liu Ying, 23, are ranked third and fourth in the Union Cycliste Internationale (UCI) cross-country world rankings and put China at the top of the international rankings for the first time following the 2007 season.