Vibration damper for portable bicycle

The utility model relates to a vibration damper for a portable bicycle. The utility model is composed of a rotating arm and a disciform spring arranged in a buffer disk, wherein, the outer end of the disciform spring is fixed on a housing, and the inner end of the disciform spring is connected with the rotating arm through a rotating shaft to form the utility model. When the utility model is used, a front fork or a bicycle frame are fixed on the housing of the buffer disk, the wheel shaft of a bicycle is connected with and fixed on the rotating arm; when bicycle wheels are bumped up and down, the upward and downward vibration of the shafts of the bicycle is converted into the rotation of the rotating shaft, the rotation of the rotating shaft is converted to the screwing and relaxation motion of the disciform spring, elastic potential energy is released or accumulated, and thus, the impact force of the vibration is lessened. The utility model has the advantages of simple structure, easy assemblage and favorable damping effect; besides, wobbling and sway are not easily generated between the bicycle wheels and the bicycle frame.