I disagree because you would be turned away at the gate. The guards will not let you on base unless you are in compliance, period.
If you are off base and are riding, you are not required to have on the fluorescent vest, but it is highly encouraged of course. If you were not planning to ride onto base and do not have your vest, you will be parking it at the gate and walking to your destination.
Actually that is not correct for all branches the AF states that during daylight hours both on and off base you must wear either the reflective vest with 24" sq in of reflective material or brightly colored contrasting colors. The uniform does not count as contrasting colors and reflective vests must be worn in uniform at all times. Durning hours of darkness you must rear the reflective vest or similar no matter on base or off.