Put an AIM mychron 3 on to your 21 and now you have laptimer water temp exhaust temp,throttle pos,G indicator,gear pos indicator,rpm,speed,data logger and on and on they look cool getting one for the race bike its a 21.Kicked an 18s ass last season and a 28 but not the Aprilia RS250 because he put most of a TZ into onto it bah.Oh then the 21 blew up cool.