Ключевые слова: athlete, back wheel, balance, bicycle, bicyclist, bike, biker, biking, black, bmx, challenge, cycle, cycling, cyclist, extreme, extreme sports, freestyle, helmet, leisure, male, man, mountain bike, mtb, people, person, rider, safety helmet, silhouette, skill, sport, sportswear, stunt, training, transport, trial, trial biking, trick, wheelie, white,