Utah Valley State College student Sam Durst, who has cerebral palsy, is thrilled with the trailer designed for him, which he and his brother are readying for market. He's 22, takes business classes and stays active - skiing, bowling, riding horses and even rappelling. Durst has cerebral palsy, and despite skiing on weekends with his family, he hasn't been able to join in family bike rides for a decade. Through Brigham Young University’s Capstone project, a team of engineering students designed a portable bike trailer big enough for him and light enough for his parents to pull him around, and which can be converted into a stroller. The trailer weighs about 32 pounds, is compact, converts to a jogger and hitches - or unhitches - easily from a bike.