Shock absorber with adjustable preload spring: preload of coil spring is adjustable, enhancing the power of spring to meet different requirements under changed circumstances, with best-matced damping, to achieve a satisfactory ride smooth and passenger comfort. Convenient adjusting construction, wider adjusting range, and excellent shock absorber performance. Damping adjustable shock absorber:damping is adjustable in use, to meet different requirements under changed circumstances. Unique flexible high speed damping constructure, combined with quality parts, lead to a stronger adaptability and superior performance, and meet your individually requirements to a maximum extent. Leacree's package; customerized package; neutral package;