A bicycle incorporating a frame with unitary components interconnecting the post with the rear wheel axle permitting of facile mounting and dismounting by a member of either sex with a vertically movable seat obviating the rider's withdrawal therefrom during bicycle stoppage; and with the bicycle being equipped with underslung pedals which may, if elected, be formed with a support stand either of nonmovable character or of toggle design for movement between retracted, inoperative and extended, operative positions by the user's foot. The bicycle also embodies a pedal actuated brake assembly designed for locking disposition upon back-pedaling and release through operation of a conveniently presented control cable; there also being a mounting for the handlebar permitting of rapid disposition of the handlebars in selected attitude without resort to extrinsic tools. Furthermore, the pedals may be provided with foot-engaging elements for safely retaining the rider's foot upon the pedal for permitting uninhibited withdrawl in the event of any contingency.