Bicycle shock absorber

The utility model relates to a shock absorber for bicycles. A movable cross casing tube and a spring are mainly arranged on shock absorbing rods respectively, and the movable cross casing tube is connected with two movable shock absorbing shafts by circular holes on the movable cross casing tube. The shock absorbing shafts are connected with a V-shaped connecting rod and a V-shaped supporting rod which are connected. Bicycles with the utility model can run under bad road conditions, so the utility model has special damping function. Besides, because the structure of the utility model is simple, the utility model can be installed on any bicycles. Because the utility model has the characteristic of upward and downward movement, a rider can feel more comfortable and safer when rides a bicycle with the utility model.