Abstract: A bicycle seat is shown which includes a shell (11) formed from plastics material which has two buttock support portions (12 and 14) separated by a slot (16). The shell (18) includes a nose portion (18) and the transition between the support portions (12 and 14) and the nose portions (18) forms hinges (20 and 22) for allowing the support portions (12 and 14) to move independently with respect to one another in arcuate fashion during pedalling motion of the bicycle. A support rail (40) is coupled to the underside of the shell (18) and may have free ends (145) which act as stops to limit the amount of movement of the support portions (12 and 14). Springs (184, 190) may be provided between the mounting rail (40) and the shell (11). In other embodiments (FIGS. 42 to 80), the seal may include chambers for receiving air to cushion and provide support for a rider.