Abstract: A high speed tire uniformity testing device which is constructed to prevent mechanical resonances in the tire load frame during high frequency testing, thereby permitting undistorted measurements of higher harmonic force variation signals from the tire. A test tire is mounted to a rotatable spindle within a housing for selective engagement with a road wheel. The housing is supported and maneuvered by a plurality of vertical and horizontal members, each member including universal joints at its opposite ends to prevent bending moments from being applied to the members. Since only tension and compression forces are applied to the members, a very stiff load frame is provided for the test tire. One of the members comprises a linear actuator which is spaced substantially away from the longitudinal axis of the housing to provide additional stability to the housing during testing.