Ratchet hub

A ratchet hub using a magnetic force for restoration as disclosed has a freewheel unit (50) and a ratchet ring (40) thereof forming a unidirectional ratchet mechanism and a magnetic assembly using a magnetically repulsive force to normally make the freewheel unit (50) and ratchet ring (40) engage mutually and allow force transmission therebetween. Once a force disengaging the freewheel unit (50) from the ratchet ring (40) surpasses the magnetically repulsive force, the ratchet ring (40) is pushed away from the freewheel unit (50). When the force disengaging the freewheel unit (50) from the ratchet ring (40) disappears, the magnetically repulsive force automatically and promptly returns the ratchet ring (40) to engage with the freewheel unit (50) again.