Abstract: An improved bead breaker mechanism in which the bead breaker is comprised of two blades held in immobile spaced relation relative one to the other, the two blades defining two spaced working faces in a common plane adapted to lie flush against the bead area of a tire when the two blades are butted against a rim's flange in initial set up position prior to breaking the tire's bead away from the rim. The blades are preferably formed from curved plates having a common curvature axis, that axis being angled relative to the median plane of the rim in a direction away from the rim's center when the two blades are butted against the rim's flange in the set up position. The curvature of the blades preferably is such that no point on the rim edge of each blade is spaced away from the rim's flange a distance greater than about two times the tire's bead core diameter when the blades are butted against the rim's flange in set up relation.