A bicycle hub assembly includes a hub having a driving tube connected one end thereof and the driving tube includes a ratchet portion and a sprocket portion respectively defined in an outer periphery thereof. A first recess and a second recess are defined in an inner periphery of the driving tube, wherein the first recess is located corresponding to the ratchet portion and the second recess is located corresponding to the sprocket portion. A ratchet unit is mounted to the ratchet portion and a sprocket unit is mounted to the sprocket portion. A first rotary member and a second rotary member are engaged with the first recess and the second recess respectively.