A pneumatic tire and wheel rim assembly of the type in which support means extends circumferentially around the rim between the bead seats to support the tire when in a deflated condition.The support means is rotatable relative to the rim when the tire is in a deflated condition and lubrication means is provided to release lubricant to facilitate said relative rotation.The lubrication means comprises a sealed container located in a recess in the radially inner surface of the support means which ruptures to release lubricant between the radially inner surface of the support means and a confronting running surface on the rim when the tire is in a deflated condition.