Wheel for pedal-assisted bikes includes: a fixed structure associable with the frame of a bike having a driving pedal crank; a circle element mounted on the structure for rotation around a main rotation axis; a propulsion disc rotatably mounted on the structure and connectable to the crank; an electric motor associated with the structure and for cooperating with the propulsion disc to motorize the circle element; and transmission elements for transmitting rotary motion from the disc to the circle element which include a first detection device for detecting the force transmitted to the circle element from the disc, and including: a first plate associated in rotation with one of the disc and the circle element; a second plate associated with the other of the disc and the circle element; at least a motion transmission part between the first plate and second plate.