AN effort is made to determine the essentials of an ideal shock-absorber and to describe the types that approach or depart from this ideal. Mathematical analysis is not used, but judgment is based on the experience of the author with various types. The requirements of a satisfactory shock-absorber are defined and the methods used by the author in culling out certain shock-absorbers that fail to meet these requirements are outlined.
By means of a machine based on the principle, of a steam-engine indicator, the energy required to move a shock-absorber throughout its cycle at varying speeds is measured and charts are obtained. When these charts are compared with a characteristic shape of diagram of a shock-absorber found from repeated trials on the road to give the most satisfactory riding, the merits or shortcomings of any other shock-absorber can be deduced from the difference in shape.
The limits of most shock-absorbers are said to revert fundamentally to a single characteristic termed “range,” which is the ability to control a car satisfactorily at high speed on relatively rough roads without interfering with the 20-m.p.h. boulevard-riding that has become so troublesome since the introduction of balloon tires and the attendant changes in spring-suspension.
The various outstanding examples of shock-absorber at present available are classified, roughly described, and their characteristics analyzed. The conclusion reached is that it should be possible to produce a two-way mechanical shock-absorber at a reasonable cost that will give the desired degree of satisfaction, be adaptable to both light and heavy cars, and meet the demands of present-day driving.
