Bareback Riding is the Sport Where Only One Competitor Knows the Rules

Bareback bronc riding is one of the most physically demanding events in rodeo... Cowboys ride the bucking horse one-handed and cannot touch or hang onto anything with their free hand. They use a leather rigging that includes a handle that resembles that of a suitcase, where riders place their hand. To make the event more difficult for the rider, they are required to lean back and spur in a highly stylized manner that never historically used in actual practice. The cowboy's spurs have to be above the point of the horse's shoulders at the first jump out of the chute and touch the horse on every jump for the full time required for a qualifying ride. They have to stay on the horse and ride with proper technique for 8 seconds in order for the ride to be judged and scored. Once the ride is complete the rider may hold onto the rigging with both hands until he is reached by the pick-up riders, who assist the rider in getting off the still-moving horse and safely on the ground. Cowboys are judged on their control and spurring technique, and the horse is judged on their power, speed, and agility. These two scores are added together to make the total with the highest possible score being 100 points. (definition from answers.com)
Here you can see Justin sporting the chaps that he made himself. The boots, chaps, spurs, glove, rigging, neck roll, protective vest, mouth guard and a beat-up cowboy hat all play an important role in the event.