"One thing I feel most passionately about: love of invention will never die,”
KarlBenz'
The invention of the gear system used in motorcars followed hot on the heels of the construction of the first automobiles. Karl Benz was the first to add a second gear to his machine and also invented the gear shift to transfer between the two. The suggestion for this additional gear came from Benz's wife, Bertha, who drove the three-wheeled Motorwagen 65 miles from Mannheim to Pforzheim—the first long-distance automobile trip.
The need for gears arises from the specifics of an internal combustion engine. The engine has a narrow range of revolutions per minute (rpm), where the horsepower and torque produced by the engine is at a maximum. The gears allow the engine to be maintained at its most efficient rpm while altering the relative speed of the drive shaft to the wheels. This allows the car to speed up or slow down while operating the engine in its optimal range.
Gears originally required "double clutching," where the clutch had to be depressed to disengage the first gear from the drive shaft, then released to allow the correct rpm for the new gear to be selected. The clutch was then pressed again to engage the drive shaft with the new gear. Modern cars use synchronizers which use friction to match the speeds of the new gear and drive shaft before the teeth of the gears engage, meaning that the clutch only needs to be pressed once.
