Category - ADI

At some point in the training of many pupils it becomes necessary to explain how the gears work. Sometimes you can do it during the controls lesson – I usually mention it briefly then – but it often makes more sense to them once they have got a basic understanding of how to make the car move. Horses for courses, as the saying goes – you adapt your lesson to the needs of the individual.

Anyway, it seems that a lot of instructors don’t go into detail at all (and that includes how the clutch works). Not having had something explained to them – whatever it is – is usually why someone is having difficulty with it a long way into their training. As far as they’re concerned, they “aren’t progressing”, so they jump ship and find another ADI.

I’ve put this little animation together to help explain how gears work. If you want to play along, don’t fiddle with it until you read the explanation that goes with it. (Sorry, this post was written a long time ago before Flash was discontinued. I’ve only just rediscovered it, so I will find a replacement shortly)

In the animation above you can see the drive gear rotating. This is connected through the clutch to the engine, so if you put more gas on it goes faster (and if you slip the clutch it will go slower).

Click the “1st” button and the first gear appears – this is connected to the wheels, and when it goes round so do the wheels. In this demonstration it’s exactly the same size as the drive gear, so for each revolution of the drive gear the first gear will also revolve once (the red marker dots show the movement). You can get moving easily, but if you want to go faster after that you need to change up.

Click on the “2nd” button and the second gear replaces first. The second gear is smaller than first and for each revolution of the drive gear it will go round 1.25 times in this demonstration. By moving to this gear once the car is moving you’ll maintain your previous speed and be able to accelerate more without the engine having to do so much work.

Click on the “3rd” button and the third gear replaces second. This gear is even smaller than second and for each revolution of the drive gear it will revolve 1.7 times in this demonstration. This will allow you to accelerate even more.

Click on the “4th” button and fourth gear replaces third. This gear is smaller still and for each revolution of the drive gear it will go round 2.5 times in this demonstration. If we assume this is the top gear, this will allow you to travel at the highest speed for your car. Obviously, that means safe speed – not necessarily the maximum speed.

Click on the “All” button and all the gears are visible. See how the marker dots all move at different speeds.

Now, you have to remember that the car weighs quite a bit – typically, about 1 metric tonne – and it takes a lot of effort to get this moving. You need as much power from the engine as you can get to start moving before you move up through the gears as you gain speed. You can get that initial power transfer using first gear.

If you choose a higher gear than 1st, each revolution of the engine has to move the car by the equivalent of more than one revolution of the chosen gear (in the demonstration), and if you are going too slow it will be too much and for the engine and it will stutter or stall. But in first gear, one revolution of the engine will move the car by the equivalent of one revolution of that gear. That requires much less effort by the engine.

The demonstration is not intended to represent actual gear sizes and ratios in a real car. It just shows how different sized gears work.

Going into too much detail is a double-edged sword – both edges of which are nasty! You will either bore the pants off 75% of your pupils, or get caught out when it turns out 5% are mechanics and know more about the gears than you do. The other 20% might just be getting too much information – information that they don’t need, but are paying for.

ADIs are supposed to teach people how to drive – not how to strip down a gearbox. Keep it simple, keep it focused, and keep it sensibly brief.

Addendum: In spite of pointing out that the above explanation is not intended to represent the exact gear ratios in a car, and that it is intended as a brief explanation for pupils about how gears work, there are still some people out there eager to put down this advice and point out that the gears are different sizes and ratios in a real car. Yes, I know. I said that already.

But for anyone who still believes that it is an instructor’s job to give physics and engineering lessons as well as driving tuition, and who is desperate to shoot holes in this tutorial, the gear ratios in the simple demonstration above came about because I started with a 25-toothed gear and went down in 5-tooth steps. They ended up as:

• 1st – 1:1
• 2nd – 1:1.25
• 3rd – 1:1.7
• 4th – 1:2.5

These numbers of teeth were chosen purely to get an animation that wasn’t too complicated, but which showed how the gearing works when moving any vehicle. In a current Ford Focus, the actual ratios are:

• 1st – 3.67:1
• 2nd – 2.14:1
• 3rd – 1.45:1
• 4th – 1.03:1
• 5th – 0.81:1
• Reverse – 3.73:1
• Final drive – 3.82:1

In other words, the drive gear is smaller than 1st, 2nd, and 3rd gears. Of course, the ratios will be different for all other Ford models (including the various Focuses), and for all other makes and models. And if you want to go still further, you could use this information to calculate the distance moved per engine revolution as long as you know the exact circumference of the tyres and then get on to the effect the differential gears have on the final power yield. Your pupils will marvel at your erudition on the subject!

I’ve got one girl who gets bored within 5 seconds if I pull her over to discuss why she tried to drive us off a cliff, and I don’t think I’ve yet come across anyone – even those studying physics at Uni, or who are apprentice car mechanics – who feel they’re paying me to lecture them on this topic.

If you’re going to lecture on something, the more detail you go into the more of an expert you need to be. Driving instructors need to recognise where their “skills” end and “nit-picking” begins.

Driving: The Essential Skills (TES) says:

The parking brake

You should normally apply the parking brake whenever the vehicle is stationary.

Apply the parking brake… unless the wait is likely to be very short.

Your foot could easily slip off the footbrake if, for example, your shoes are wet or if you’re bumped from behind. You could then be pushed into another vehicle or a pedestrian…

The use of the parking brake is even more important in vehicles fitted with automatic transmission. The parking brake will help avoid

• the possibility of ‘creep’
• the vehicle surging forward if the accelerator is pressed accidentally while in D (Drive)

Although it might seem a controversial comment to make, the people who learn in automatics tend to be the kind who can easily get their feet mixed up, so that second warning is very relevant. It’s bad enough in a manual with some learners.

TES also says:

Section 22 Automatics and four-wheel drive

The importance of the parking brake

Fully applying the parking brake whenever your vehicle is stationary is even more important on an automatic.

If the selector lever is in any position other than P or N, it will move off under power if the accelerator is pressed (accidentally or on purpose) unless the brakes are on.

If the choke (manual or automatic) is in use, an even lighter accelerator pressure can move the vehicle away.

I view of this, it is surprising to see some ADIs advising that you shouldn’t use the parking brake in an automatic. This alternative advice seems to be based on the belief that the drivers in question find it difficult to apply, or that automatic drivers historically have fallen into the habit of not using it. It even appears that some ADIs purposely criticise use of the handbrake because they believe that a pupil’s previous instructor told them to use it every time they stop!

Let’s just set a few records straight. First of all, brake light glare is a very real problem. At night – and especially if it is raining – modern high-intensity brake lights can be painfully bright. TES says:

Junctions at night

Brake lights can dazzle. Don’t keep your foot on the brake pedal if you’re waiting at a junction or queuing in traffic… use the parking brake.

[Similarly with indicators]

Sitting at traffic lights with your foot on the brake is ignorant as well as the sign of a bad (or badly taught) driver.

Secondly, there are many things that learners are taught to do or not do when they are taking lessons. A good example would be adhering to speed limits. The simple fact that many of them choose to ignore speed limits totally once they pass does not mean they are right, or that ADIs should start teaching that way too. For that reason, the apparent fact that most automatic drivers fall into the lazy habit of just sitting there with their foot on the brakes does not in any way make them right or indicate that ADIs who teach in automatics should fall into line.

Going back to the comment I made above, people who learn in automatics very often do so because they can’t handle manual cars. I’ve persuaded several to move to automatics because they just don’t have the coordination to handle the clutch, gears, and brakes. Once they pass their tests, that lack of coordination is bound to lead to not using the handbrake for most of them. But it doesn’t mean they’re right – it just means they’re not very good drivers! (Before anyone rises to that, just think: no matter how nice someone is, how dedicated they are to learning, how desperate they are to pass, whatever their disability or other domestic circumstances, etc., it has no bearing whatsoever on whether they are a good driver or not. It’s just the way it is.)

On the driving test, you won’t immediately fail for not using the handbrake. But you will fail if not using it leads to some other problem, or even if the examiner perceives that there is a significant risk. ADIs shouldn’t be making their own rules up just to fit in with difficult learners.

Not using the parking brake by default is already half way to a fail. And nearly all of the way to being a bad or inconsiderate driver from the moment they get their licence!

But some automatics don’t have a parking brake.

All modern cars have some sort of parking brake. The dangers of not using it have already been outlined. Whether you operate it with your hand, your foot, or through some sort of telepathy, it is there for a reason.

If you’re stopped, brake light dazzle isn’t going to cause an accident, is it?

Driving at night and having to put up with dazzle can lead to tiredness or loss of concentration or awareness. Having bright lights shone unnecessarily in your face in uncomfortable at best, but can potentially lead to more dangerous situations.

If you are teaching people to avoid using the handbrake and not teaching them to think of those behind them, you need to take a serious look at what you are doing. Brake light dazzle IS a significant problem. Holding the car on the footbrake for too long, and especially at night, IS a sign of a bad or inconsiderate driver.

I hate it when I pick up pupils who have been told to use the handbrake every time they stop.

Well, good for you. However, you ought to allow for the fact that most new drivers find it difficult to assess when to do something that should be triggered by judgement or common sense, and often fall into the habit of either always doing it, or always not doing it as a result. They try to pigeon hole everything. So there is a good chance they were not actually told to apply the handbrake “every time”, but have developed that habit themselves as a “just in case” strategy (they do it with signalling to pull over or move off, amongst other things). Mine often try to do it, in spite of me never having taught them to.

TES makes it clear that you should use the handbrake where it would help you prevent the car from rolling.

So it comes down to two options for many learners. Do you:

• NOT use the handbrake and risk rolling?
• use it EVERY TIME just in case?

Only the first one carries any significant risk. The second is not a fault, nor is it a danger to other road users in itself. The only people who see it as a problem are certain ADIs who seem annoyed by it.

Someone found the blog on that search term! It depends on many factors including where you teach. Someone teaching in Central London is hardly going to be able to cover as many miles as someone in a less urban location.

Taking my own pupils as an example, a typical 2 hour lesson can cover anywhere from less than 5 miles to more than 60! It just depends on what you are trying to cover.

The one thing to remember is that although some people can learn new things very quickly, the one thing that cannot be hurried is experience. By definition, experience only comes with time and practice, and that means time on the road practicing driving. Inevitably, that translates into miles.

Many pupils are anxious about how much it will cost them to learn to drive, and I make it clear from the outset that if they can get a lot of quality private practice between lessons then they will learn over a shorter time period. I just tell them straight that if they can get insured on mum or dad’s car then that will avoid having to pay me for the road time instead. I also tell them that it is important that mum or dad prevents bad habits forming, so I suggest that they accompany us on a lesson and I show them some things to watch out for.

If I get someone who passes quickly (especially without any private practice) then I feel glad for both them and me. But I always have a nagging worry that they might not have had enough road experience to drive safely once they’re out on their own. That’s why I don’t try to scrimp on fuel and am happy to drive long distances and do manoeuvres a long way from the test centres.

I know that the primary consideration for many ADIs is fuel costs. I’ve written before about the cheapos and their stupid hourly rates. That’s one group that will avoid racking up many miles like the plague, because it eats into their already tiny profit margin.

An ADI should be teaching their learners whatever is necessary to make them safe new drivers once they pass their tests, and make allowances for whatever they are/are not doing in between lessons.

An ADI should not be teaching the bare minimum required to pass the test.

You can work out for yourself which of those groups the cheapos are likely to fall under.