The correct term that describes the force keeping the outside of a bicycle wheel from flying off is centripetal force.
Centripetal force is the net force that acts on an object moving in a circular path, directed toward the center of that path. In the case of a bicycle wheel, the tension in the spokes and the forces exerted by the axle help provide this centripetal force, keeping the wheel (and its components) in circular motion and preventing it from flying off outward.
"Centrifugal force" is often mentioned in discussions about circular motion, but it is not a real force; rather, it is the perceived force that seems to push objects outward when viewed from a rotating reference frame. However, it does not actually act on the wheel or any of its components.
4 answers