This invention is improve integral screw-nut of conventional quick-release hub to include a screw-nut with a washer, so as to achieve a spherical locking device with micro adjusting function, and the improved screw nut engages with a shaft stably to prevent inner and outer teeth from disengagement. No matter unlocking or locking the seat clamp, the quick-release grip has an unsharp and smooth outer surface to be rotated at 360 degrees, thus operating smoothly and comfortably. During locking operation, the curved quick-release grip matches with a front / rear fork to prevent from disengagement during shock enhancing safety.