I have Citizen Tokyo that belongs to my daughter. My daughter is now riding my Dahon Boardwalk so I want to give the Citizen to my son for next season. He is tall for his age - about 50 inches and 64 pounds. The Citizen web site says that the Tokyo is recommended for teens and adults that are 5'0-6'0 ft tall but the bike is so small and the handlebars are adjustable. What do you think?