A motorized bicycle gear shift device comprising a derailleur and an electric motor, associated directly with the derailleur, for controlling the derailleur and an electric transducer of absolute type, also associated with the derailleur for producing an electric signal indicative of the absolute position of the movable body of the derailleur. A plurality of sets of channel quality indicator information may be stored for each of a plurality of UE communication scenarios. The channel region is in mechanical tension on the first side and in mechanical compression on the second side.