Race Tech has recently developed a lighter shock spring rate for smaller riders. The SRSP 5524 Series Shock Springs now comes in a 4.0 kg/mm spring rate which will accommodate a rider weighing around 80lbs. This new rate fits the popular mini bikes with 40mm shocks. Race Tech's High Performance Shock Springs are made using the highest quality materials and processing. The springs have extremely close tolerances and are shot-peened, heat treated and pre-set for "no sacking". For an exact spring rate that is optimum for your rider weight, please visit racetech.com and the Spring Rate Search.The SRSP 552440 retails for $109.99 and is available by contacting Race Tech Sales at 951-279-6655 or email@example.com.