A stationary bicycle with a frame. A crankset is rotatably mounted to the frame to receive a pedaling actuation from a user of the stationary bicycle. A seat is mounted to the frame to support the user using the crankset in the pedaling actuation. A handlebar is mounted to the frame to serve as a hand/arm support for the user during the pedaling actuation. Translational joints between the frame and the seat and the handlebar are provided for translational displacement of the seat or handlebar with respect to the crankset. A mechanism is connected to the translational joint for locking the translational joint in a selected position, the mechanism allowing movement of the translational joint solely by a selected actuation displacing the translational joint proportionally in the direction of the translational displacement.