1. APPARATUS FOR PROTECTING A TIRE BY PREVENTING WITHDRAWAL OF THE VALVE STEM THROUGH AN APERTURE IN THE RIM AND INTO THE INTERIOR OF THE TIRE CASING AND COMPRISING, A RIGID PLATE HAVING AN OPEN ENDED SLOT IN ONE END THEREOF TO RECEIVE SAID STEM AND BEING ADAPTED TO LIE FLAT AGAINST THE RIM IN THE VICINITY OF SAID APERTURE, A SUBSTANTIALLY FLAT CENTRAL BODY PORTION FOR SAID PLATE EXTENDING GENERALLY PARALLEL TO SAID STEM AND TERMINATING NEAR THE VALVE END OF SAID STEM, AN INTEGRAL BENT-OVER PORTION OF SAID PLATE WHICH AT LEAST PARTIALLY ENCIRCLES SAID STEM NEAR THE VALVE END THEREOF, AND FASTENING MEANS THREADABLY ENGAGING SAID BENT-OVER PORTION AND BEING ADAPTED TO BEAR TIGHTLY AGAINST SAID STEM AND THEREBY FORCE SAID STEM AGAINST SAID BENT-OVER PORTION WHICH AT LEAST PARTIALLY ENCIRCLES SAID STEM.