The wheel (1) for pedal-assisted bikes comprises: a fixed structure (2) having attachment means for the attachment to the frame (T) of a bike (B) with a driving pedal crank (P); a circle element (10, 11, 12) mounted on the fixed structure (2) in a revolving way around a main rotation axis (A); a propulsion disk (13) mounted on the fixed structure (2) in a revolving way and drivable in rotation by the driving pedal crank (P); motion transmission means (15, 16) for the transmission of the rotational motion from the propulsion disk (13) to the circle element (10, 11, 12), which comprise at least a first detection device (16) suitable for detecting the driving torque transmitted to the circle element (10, 11, 12) from the propulsion disk (13); an electric motor (54, 55) associated with the fixed structure (2) and suitable for cooperating with the propulsion disk (13) to motorize the circle element (10, 11, 12); and a processing and control unit (57, 58) operatively connected to the first detection device (16) and to the electric motor (54, 55) and suitable for controlling the activation of the electric motor (54, 55) according to the driving torque detected by the first detection device (16); wherein the first detection device (16) comprises: a measuring element (61, 62) which is subject to a stress condition due to the effect of the driving torque transmitted to the circle element (10, 11, 12) by the propulsion disk (13); and at least a measuring sensor (63) which is arranged in correspondence to the measuring element (61, 62) and which is suitable for detecting the stress condition of the measuring element (61, 62) and for producing a corresponding electronic signal which can be processed by the processing and control unit (57, 58).