A system for acquiring the angular position of a gas twist grip in a motorcycle; the acquisition system is provided with a fixed supporting body; a rotating shaft turnable mounted in the supporting body; a transmission device mechanically connected to the gas twist grip and to the revolving shaft to transmit the motion of the gas twist grip to the revolving shaft itself; a main angular position sensor, which is carried by the supporting body, is coupled to the revolving shaft to determine the angular position of revolving shaft, and is adapted to provide two reciprocally redundant measures of the angular position of the revolving shaft; and an angular control position sensor, which is carried by the supporting body, is coupled to the revolving shaft to determine the angular position of the revolving shaft, and is adapted to provide two reciprocally redundant measures of the angular position of the revolving shaft.