Flat-track may be new to X Games, but it's one of the world's oldest motorcycle racing disciplines. And on the evening of June 4, Harley-Davidson Flat-Track Racing debuted at — and kicked off — X Games Austin 2015.
Flat-track is simple to describe: Riders on high power-to-weight ratio motorcycles race counter-clockwise around dirt ovals. In high-speed corners, the bikes get pitched sideways as the left foot, shrouded in a handmade steel shoe, helps riders guide their way through power slides. Front brakes are removed to save weight. Speeds vary depending on track length — typically anywhere from a quarter-to one-mile long — but a 750cc twin cylinder motorcycle with 90+ horsepower exceeds 130 mph at the Springfield Mile (note that the X Games track will be shorter and speeds are not expected to be as high).
The origins of flat-track, also referred to as dirt track, are almost as old as the invention of motorcycles. In the early 1900s, motorcycles were used to help pull bicyclists up to a speed that kept them on the wooden banks of velodromes, which could be 45 degrees. The motorcycles soon replaced the bicycles, and "board track" became one of the most popular forms of racing in the United States.
Dirt races were already happening during the board track era and became the preferred motorcycle discipline. In 1924, on a one-mile dirt oval in Toledo, Ohio, Jim Davis won the first national race sanctioned by the American Motorcyclist Association (AMA), which was founded that year. In 1954, the Grand National Championship (GNC) was formed, the foundation of the AMA flat track series that still operates today.
Rules, bike specs, format structures and class names have changed many times since 1954, but the gritty, high-speed roots of the sport remain. In 2015, the division names at the professional level were renamed to GNC1 and GNC2, the former being the top level of the sport and the class in which X Games riders participate.
The equipment used in X Games Harley-Davidson Flat-Track Racing will be the same the AMA Pro Flat Track GNC1 riders use on half-mile and mile tracks. X Games will follow AMA Pro Flat Track rules. Twenty-four athletes have been invited to compete on an oval made of red clay, which will be hardpack and sticky. The inside will be 1,750 feet (1/3 mile) and the outside 2,258 feet (7/16 mile). The track is a little short compared to AMA Pro Flat Track twin-cylinder competition. Lap times are expected to be between 20-25 seconds.
In Austin, the 24 competitors will qualify down to a single 12-rider final (June 4 at 8:30 p.m. ET on ESPN). Unique to XG, the 12 riders will start behind a motocross-style starting gate with a 30-second countdown. In AMA Pro Flat Track, riders are gridded on three rows of six riders and use starting lights.
This article originally appeared on ESPN.