A conical disk pair for a belt-driven conical-pulley transmission includes a fixed disk, and a movable disk that is axially movable and rotationally fixed to an input shaft. A torque sensor is associated with the movable disk on a side opposite from the axially fixed disk and includes a sensing piston having axially-directed arms that are circumferentially spaced on a side of the sensing piston that faces away from the movable disk. The arms have outer axially—extending teeth that mesh with inner axial teeth of an input wheel. An inner support ring contacts the arms on an inner side radially opposite the outer teeth of the arms and forces the outer teeth of the arms into meshing engagement with circumferentially-positioned axial teeth of the input wheel.