An air spring (1) has a cylindrical flexible sleeve (2) secured at each end to form a fluid chamber (14). One end (6) of the sleeve (2) is secured to a retainer (8). The retainer (8) has a ribbed reinforcement structure (16) which allows the air spring (1) to be directly mounted to a moveable part of a vehicle or other machinery. The retainer (8) has an extending mounting structure (13) on one side of the reinforcement structure (16) and a bead-seating surface (12) adjacent to the reinforcement structure (16).