A mechanical ratio adapter is a small gearbox used to increase or decrease the rotation speed of the cable on a mechanical speedometer. Ratio adapters can be installed anywhere in the system, such ...

Speedometer adapter ratio = 1,000 x speedometer drive gear number. tire revolutions per mile x rear axle ratio. Note 1: To determine your speedometer drive gear number, ...

VDO Instruments (116 Victor, Detroit, Michigan 48203, or 6109 Lankershim Blvd., North Hollywood, California 91606) recommends the following method to determine the new speedometer ratio you must ...