A pneumatic tyre

摘要

A pneumatic tyre for mounting on a normal rim, comprising a pair of beads (2) each having a bead bottom surface (2a) seating on a rim seat (12) of the normal rim and bead outer surface (4) connected to the bead bottom surface (2a) and arranged to abut a rim flange of the normal rim, characterised in that the bead outer surface (4) has exhaust means (6) extending outwards in the radial direction from an inner end (D) of the exhaust means (6) so as to form an air passage for escaping air from between the rim flange (11) and the bead outer surface (2a) on assembly of the tyre and rim, and the inner end (D) of the exhaust means (6) is positioned within a region remote from a bead base line by a distance of 0.5 to 1.5 times a separating point height Fh defined as the height in the radial direction from the bead base line to a separating point (B) at which the bead outer surface (2a) separates from the rim flange (11).