A vehicle frame includes a head tube, a fork, and a rotation limiting mechanism. The fork includes a steerer that extends rotatably through the head tube. The rotation limiting mechanism is operable so as to limit rotation of the steerer relative to the head tube, and includes first and second positioning units, and an engaging unit. The first positioning unit is coupled to the head tube. The second positioning unit is coupled to the steerer. The engaging unit engages releasably the first and second positioning units to thereby limit rotation of the steerer relative to the head tube.