Advanced aero frameset the ar5 takes felts wind tunnel designed ar frame and their uhc performance carbon fiber to deliver aero performance with no compromises the aerodynamic advantage of the ar5 plus the efficient shimano 105 drivetrain will help you gain speed and save precious energy whether completing a century or dropping your friends on the club ride shimano 105 11 speed groupset light action vivid shifting is just one of many features taken from shimanorsquos top end groupsets ma