Abstract: A shock absorber testing apparatus comprising a ramp shaped to excite a particular wheel of an automobile at a frequency bandpass intermediate the fundamental frequency of the automobile spring-mass system and the fundamental frequency of unsprung elements of the suspension, measured by strain gages disposed on the ramp sensing ramp deformation due to the wheel loading as the wheel is passed thereover, and including switch means discriminating between the front and rear wheels selecting alternate storage circuits receiving the respective strain gage reading associated with each passing of the wheel. In one further embodiment, the storage circuits include peak detectors connected to the strain gages on each side of the ramp and means for comparing the peak detector outputs for producing a signal indicative of the difference therebetween.