|
|
|
|
|
We have now reached Phase 4 in our study of the System of Car Control. In theory, the gear phase is quite straightforward – once you have the right speed for the circumstances, you select the correct gear for that speed – ‘Brake to slow, Gear to go’. You should normally complete the braking (speed) phase before changing gear. Use of gears is covered in some detail in Chapters 2 and 4 of Roadcraft.
Changing Gear
Roadcraft does not have much to say about the actual process of changing gear. However, the Roadcraft video does, and it is worth summarising here.
You should always change gear smoothly. Most gearboxes are arranged so that the gear lever is spring-loaded into the plane of 3rd and 4th gear. So, if you push the gear lever straight forward from neutral, it will go into third; pull it straight back and it selects fourth. It follows, then, that all the other gears will need some sideways movement as well, to get the lever out of the 3rd/4th plane. If you put your palm on the lever and select first gear by pushing to the left and forward, the gear lever can slip out of your hand; the same applies to second gear. So the Roadcraft video advises you to place your left thumb facing downwards alongside the gear lever when selecting first or second gear. The sideways movement, combined with moving the lever forwards or back, should be a diagonal movement, not an L-shape, to result in a smooth gear change.
Many drivers try to change gear too quickly, which can cause a jerky change. To avoid that, count ‘one thousand, two thousand’ as you make the change, and even pause momentarily as you pass neutral. If you feel that you have to ‘snatch’ the gear change, you are probably leaving it too late.
Jerky gear changes can also occur if you do not match the revs when changing gear. If you take your foot off the clutch suddenly, like an on-off switch, after you have changed gear, the car will jerk as the transmission drags the engine speed up to match the road speed. The correct way is to release the clutch gently at the same time as depressing the accelerator; if you get it right, the gear change will be imperceptible to your passengers. Indeed, if you get it exactly right, you don’t need to use the clutch at all – but I wouldn’t recommend experimenting with that in your own car! More advanced gear-changing techniques include using constant revs, rather than releasing the accelerator during the gear change, and double declutching; however, those are outside the scope of this article.
The Wrong Way
The two most common mistakes made by new IAM associates (and probably also by some full members who should know better!) are brake/ gear overlap and secondary braking. These both arise from not following the phases of the System in the correct order, or not allowing sufficient time for them. Remember the slogan: ‘Speed for the hazard, Gear for the speed’, or, if you prefer: ‘Brake to slow, Gear to go’.
If you find that you are changing gear whilst still braking (brake/gear overlap), you probably need to brake harder, or sooner, or both. One situation where brake/gear overlap is acceptable is when turning sharply, usually into a junction on the left, from a road which is downhill. Otherwise you should remove your foot from the brake pedal before changing gear.
Secondary braking is braking again after you have changed gear; that is caused by not braking enough in the first place. Sometimes, however, you can explain that away by claiming that the situation changed after you had changed gear and you are re-running the System from that point. We will discuss both these errors in detail in another article in this series.
Using the Gears
Many drivers try to get Into top gear (usually 5th) as fast as possible, and seem afraid to use the intermediate gears. Many are reluctant to rev the engine, believing that it will cause damage or premature wear.
In fact, lower gears give better balance and control for all driving except high-speed cruising. Intermediate gears are useful in towns: IAM Fact Sheet 16/001 recommends that drivers use 3rd gear in a 30-mph speed limit, both to conserve fuel and to make it easier to stay within the speed limit (see the March 2004 issue of One Way).
It is a good idea to learn the maximum and best speeds for each gear in your car, by reading the manual and by trial and error. You can do this by finding a section of winding country road that you know well and driving along it in 3rd gear. Then, within the bounds of safety, drive along it again in 4th gear and again in 2nd or 5th, as appropriate, to discover which gear gives you the best balance and control.
We have been referring throughout this article to manual gearboxes. Drivers of automatics should be prepared to get the best from them by using low-gear hold and other characteristics of their particular vehicle. We carried a very informative article on automatic gearboxes, from the RoSPA Advanced Drivers’ Association (RoADA) web site, in the July 2003 issue of One Way. To see it, visit www.roada.org.uk and click on Articles.