Ключевые слова: acrobatics, action, adventure, athlete, bicycle, bicycling, bicyclist, bike, biker, biking, bmx, boy, cool, cycle, cycling, cyclist, danger, dirt, dirtjump, extremal, extreme, fall, freestyle, helmet, jump, lifestyle, man, one, outline, people, person, rider, riding, silhouette, skills, sky, sport, stunt, style, superman, transport, transportation, trick, urban, vehicle, wheel, young, youth,