Bicycle gearshift, comprising: - a first body configured to be associated with a bicycle frame; - a second body connected to, and moveable with respect to, said first body; - a rocker arm rotatably connected to said second body at a predetermined rotation axis; - an elastic element configured to push said rocker arm in rotation about said rotation axis in a first direction of rotation; and - an unidirectional damping device operatively arranged between said rocker arm and said second body and configured to apply a friction force to said rocker arm when said rocker arm is moved about said rotation axis in a second direction of rotation opposite to said first direction of rotation; characterized in that said unidirectional damping device comprises: - a first ring nut arranged coaxially to said rotation axis and rotatable as a unit with said rocker arm about said rotation axis, said first ring nut being fixedly connected to said rocker arm and comprising a first front saw-toothing; - a second ring nut arranged coaxially to said rotation axis in a position axially adjacent to said first ring nut, said second ring nut comprising a second front saw-toothing matching said first front toothing; - an actuation system configured to actuate the unidirectional damping device, said actuation system acting on at least one ring nut of said first ring nut and second ring nut to axially push said at least one ring nut towards the other ring nut of said first ring nut and second ring nut so as to mutually engage said first front toothing and said second front toothing when said rocker arm is moved about the rotation axis in said second direction of rotation; - at least one first friction surface being part of, or associated with, said second ring nut; - at least one second friction surface being part of, or associated with, said second body and configured to slide on said at least one first friction surface when said rocker arm is moved about the rotation axis in said second direction of rotation. - a first body configured to be associated with a bicycle frame; - a second body connected to, and moveable with respect to, said first body; - a rocker arm rotatably connected to said second body at a predetermined rotation axis; - an elastic element configured to push said rocker arm in rotation about said rotation axis in a first direction of rotation; and - an unidirectional damping device operatively arranged between said rocker arm and said second body and configured to apply a friction force to said rocker arm when said rocker arm is moved about said rotation axis in a second direction of rotation opposite to said first direction of rotation; - a first ring nut arranged coaxially to said rotation axis and rotatable as a unit with said rocker arm about said rotation axis, said first ring nut being fixedly connected to said rocker arm and comprising a first front saw-toothing; - a second ring nut arranged coaxially to said rotation axis in a position axially adjacent to said first ring nut, said second ring nut comprising a second front saw-toothing matching said first front toothing; - an actuation system configured to actuate the unidirectional damping device, said actuation system acting on at least one ring nut of said first ring nut and second ring nut to axially push said at least one ring nut towards the other ring nut of said first ring nut and second ring nut so as to mutually engage said first front toothing and said second front toothing when said rocker arm is moved about the rotation axis in said second direction of rotation; - at least one first friction surface being part of, or associated with, said second ring nut; - at least one second friction surface being part of, or associated with, said second body and configured to slide on said at least one first friction surface when said rocker arm is moved about the rotation axis in said second direction of rotation.