An air maintenance tire assembly includes a tire having a tire cavity bounded by first and second sidewalls extending to a tire tread region and air pumping means for generating pressurized air for maintaining air pressure within the tire cavity at a preset pressure level. The air pumping means includes an upper mounting plate fixed to a vehicle rim, a lower mounting plate fixed to the rim and diametrically opposed to the upper mounting plate, a dynamic mass pivotally attached to the upper mounting plate at a first end of the dynamic mass, and a pump fixed to the lower mounting plate and pivotally attached to a second end of the dynamic mass.