The present invention relates to an apparatus and method for allowing visual access to the interior of a tire wheel assembly under dynamic conditions. More particularly, the present invention relates to a wheel rim having a window or access area such that the interior of a tire mounted on the wheel rim may be viewed under dynamic conditions such as those provided by a dynamometer test machine. A method is also presented in which a camera and strobe light are used with the wheel rim having at least one window to record the reaction of flowable materials inserted into the pressure chamber of a tire wheel assembly at the tire footprint under loaded dynamic conditions. An alternate embodiment includes the camera and the light attached to the wheel.