How To Drive A Motorcar
A Key To The Subtleties Of Motoring

CHAPTER XI Gear-changing Downwards and Trick Changes IN viewing the aspect of the case of gear-changing when going to a higher ratio, we have seen that it is the easier part of the work, the chief desideratum being a pause before making the change, which in most cases is provided automatically by the nature of the movement to be made, so that very much, skill is not needed in effecting these changes in a reasonably good manner. A four-speed gearbox has been dealt with, as it is easier to argue from the four to the three than vice versa. The only difference worth recording is that with a four-speed gearbox the pauses to be made are less than with a three-speed gearbox, as the difference between the ratios is naturally smaller. There is another small point, which may be mentioned to com- plete the substance of the main variations, and that is the necessity of taking into consideration the diameter and weight of the revolving portions of the clutch mechanism. If they are heavy, then a longer pause will be necessary. If they are light the momentum stored in them is not so great, and they will come to rest more quickly, and consequently a shorter pause is requisite. Finally, there is the question of the clutch stop which has to be considered. It is provided to minimize the pause which is requisite, and there, of course, the same line of argument carries weight. If the clutch stop is efficient, the pause will be small ; if not, slightly longer. In some few cars, within the realm of the writer s practical experience, the clutch stop is so efficiently 93