Abstract: In an infinitely variable traction roller transmission wherein two toric traction discs are rotatably supported opposite one another so as to define therebetween a toric cavity in which at least two motion transmitting traction rollers are disposed in engagement with the toric discs and supported by trunnions which are pivotally supported to permit changing the ratio of motion transmission between the toric discs, each pivot trunnion has a cylindrical cavity with a support piston disposed therein in axial alignment with the traction roller supported on the trunnion and a plurality of radial lever members are arranged around the axis of the support piston and rest on a fulcrum structure disposed around the cylindrical cavity and, at their inner end, on the support piston, and a bearing disc which carries the traction roller is supported on the radial lever members at a location inwardly from the fulcrum structure to force the traction roller into engagement with the toric discs with the piston force amplified