A tubeless tire and rim assembly including an annular bead lock in the form of an endless train of lock elements interconnected by flexible joints. The bead lock can have not only a fully expanded circular configuration to fit over the rim base but also a partly folded configuration to lie within the inner peripheral circle of the tire. This particularly facilitates the mounting of such bead lock while effectively preventing any improper positioning thereof. An embodiment incorporating a flat-protector together with the bead lock is also contemplated to further improve the driving safety.