You can put it either way, if your control rods are long enough I would put the "wheel" it towards the front of the wing so you have a little more room for error for postioning the rods. I would also take off the wheel and put one of the hex or star shaped servo arms on to get more range for setting throw. The wheels work better on the throttle servo or the elevator, the rudder/nose wheel work better with the hex or star arms. Just my opinion though.