I’ve had a few hits on the rolling back and clutch/brake posts as a result of the search term “how do you hold the clutch so you don’t roll back”, “how to find the bite”, and (my favourite) “how to drive – find the bite”.
This is best dealt with by the instructor, because it is one of those things that is easier if you are doing it instead of just talking about it. But the first thing to do is get a rough idea of how the clutch works – not in technical detail, just very roughly.
When you turn on the engine, you have to be able to transfer the power to the wheels somehow. So the engine is connected to the wheels via a drive shaft – to start with, imagine you are in a car that has no clutch or gears.
As soon as you started the engine, it would turn the drive shaft, and that would turn the wheels – so the car would move forward (see diagram to the left). But this is a useless situation for controlling the car, because if you braked and stopped the car, the drive shaft couldn’t turn, so the engine would stall. And if you didn’t brake, the car would just go forward out of control.
So, the drive shaft has a break in it (see diagram to the left) – this is the clutch assembly. You can think of it as two discs, one connected to the engine-end of the shaft, the other to the wheels-end of the shaft.
The drive shaft also has a second break in it – this is the gear-box – but I haven’t put it in the drawings.
When the engine is running, and the car is in gear, with the clutch pedal all the way down the two discs are pulled completely apart. So the engine makes one of them spin (the orange section in the diagram).
If you gently raise the clutch pedal, the two discs get closer and closer together. As soon as they begin to make contact with each other – this is the bite (or biting) point – the engine is able to start trying to move the the wheels. If the handbrake is on you’ll feel a slight bump as the system starts to take the strain. You may also feel the car dip slightly at the back (look in your rear view mirror). And you might hear the engine sound change slightly, or see the rev counter fluctuate.
The trick is to be able to find the bite point quickly and reliably and to keep your foot still once you have. If you lift your foot too far past the bite point, the engine will start to strain and may stall (it’s also bad for your clutch), or the car could lurch forward if you take the handbrake off.
For completion, it is necessary to point out that with the clutch pedal all the way up and the two discs pushed hard together, you have the same situation you would have if you had no clutch at all – except that by pushing the pedal down again, you can get control of the car as you need it (and change gears).
I teach my pupils to find the bite without any gas to begin with (and I mean on the first lesson). If you can do it with no gas, and without stalling, you are doing well.
The next trick is to be able to set the gas, then find the bite. A lot of pupils I find have initial problems keeping their feet separate from each other, and as they find the bite they release the gas (and vice versa). But practice makes perfect.
I have a number of exercises I do with my pupils to get them to be able to hold the car on the bite quickly so that they can deal with junctions confidently.
(This is a simplified way of describing the clutch to people who really aren’t interested in detailed mechanical explanations. I know some ADIs who revel in providing diagrams of the actual clutch assembly, but this is more for their benefit than their pupils.)
One final thing: if you are paying for lessons all of this should be taught to you on the first lesson, and definitely by the end of the second. Even if you only take hour lessons, if you are sitting stationary listening to a lecture about the controls the whole time you are quite possibly being taken for a ride (no pun intended). You shouldn’t have to sort this out for yourself – it’s absolutely fundamental to a driving instructor’s syllabus and it’s what they get paid to teach.
I get a lot of pupils who have either skipped instructors because they weren’t getting anywhere, or who are amazed at what they do compared to their friends who are with other ADIs on our lessons. ADIs try to explain it away as pupils telling lies to cover up their inadequacies, but I find so few – either taught by me from scratch, or who I pick up partly trained – who can’t progress at a reasonable rate that I cannot accept there are so many learning elsewhere who apparently are deficient in some way.
Common questions/concerns:
Do I need to set the gas when finding the bite?
Technically, no. However, if you don’t have the gas set the car will easily stall, and you won’t be able to move away quickly to take advantage of lights changing or gaps appearing. Both of these can lead to problems with you causing hold-ups due to hesitation or simply stalling – and you know what that means if you’re on your test! So most of the time you will want to set the gas.
How can I find the bite quickly?
Practice! It isn’t rocket science, but neither is it reasonable to expect to be able to do it the first time you get in a car. It takes time to perfect, and some people pick it up better than others. A good exercise is to put the car in gear, then repeatedly find the bite, de-clutch, find the bite again, and so on… over and over again, but without stalling. Then try it with setting the gas first – exactly the same way, but set the gas, then find the bite, then de-clutch/off the bite, then repeat… again and again. Try to put it into practice every time you move off (from a parked position, from lights, at junctions, on hills, and so on). Your clutch ankle will develop a “memory”, and both your feet will gradually develop synchronisation.
Another exercise is to find a gentle uphill slope, drive slowly up it a little way, then take your foot off the gas and de-clutch. As the car rolls to a stop, set the gas and bite to hold it still. Then drive a little further and do it again. Obviously, someone needs to keep an eye on what’s going on behind – it has to be a quiet road – but concentrate only on the gas and bite at this stage. When I do it with my pupils, I do all the checks and operate the handbrake – I want them to just concentrate on the pedals.
Once you develop the habit, you’ll wonder why you ever had trouble with it. It’s like anything new – a new computer game, learning to juggle, playing an instrument, and so on. You can’t do it first time, but you get better each time you try.
Another tip is not to think too much about what your feet are doing. The more you think about what’s going on in the floor well, the more you will hesitate and doubt what you’re doing is right.
Do you keep your foot on the biting point while driving?
No. Not when you’re driving normally. If you even rest your foot on the clutch pedal when driving you run the risk of causing the plates to slip needlessly, and that will lead to increased wear. It can cost a lot of money (upwards of £500 on some cars) to replace the clutch, so it’s not something you want to have to do regularly. Driven properly, a clutch should last easily more than 60,000 miles (well over 100,000 miles isn’t uncommon).
If you are driving slowly – in heavy traffic, for example – then you might want to use the bite to control the car’s speed in some cases, but only for short distances. At very low speeds, if you can’t have the clutch all the way up you don’t want to have it at the bite all the time for the reason given already. It makes sense to alternate between coasting and giving it a nudge with the bite in such cases (coasting at 1mph is not the same thing as coasting at 30, 50, or 70mph).
Remember also that most new-ish cars will drive themselves with the clutch all the way up in 1st and 2nd without stalling, and timing your driving and clearance to cars in front so you can just let the car cruise with the clutch fully up is another good technique to learn when in heavy traffic.
You should avoid holding the biting point for extended periods to prevent unnecessary wear.
Can you find the biting point with the foot brake on?
Yes, but I do not recommend it. Try this experiment.
With the hand brake on, and your foot OFF the foot brake, find the bite a few times (with or without gas – it doesn’t matter). Feel how the car bounces underneath you.
Now try the same thing with your foot firmly on the foot brake (you can leave the hand brake on or take it off – it doesn’t matter). There is no bounce at all, and you may even stall it before you realise you have the bite.
If you have the foot brake on, you cannot apply gas while you find the bite. And you get no feedback (that bouncing) telling you how much bite you have. If you misjudge it you will stall. On test – where you’ll be nervous – that could easily make the difference between a pass and a fail, and in normal driving it could be dangerous if you stall in the wrong place.
My advice is not to do it unless you really know what you’re up to.
How often should I hold the car at the bite?
Use it when you need it – for very short periods. As I explained above, doing it too much wears the clutch plates out so use your own common sense. If you try to second guess traffic lights or queues of traffic and end up having to stop – especially on upward slopes – use the handbrake instead.
Can you find the biting point by pushing the clutch down ?
Yes, of course you can. Using the analogy of the volume control on your ipod, you can turn it up to the ideal level if it’s too quiet, or down to the ideal level if it’s too loud. The biting point is the ideal position to hold the car balanced – not moving forward and not rolling back – so it doesn’t really matter which side you come in from. Generally, though, it’s easier to find it from below because you get feedback from the car as the bite takes hold.
How do you explain the biting point to a learner?
You can (hopefully) pick this out of the explanation I gave above, but in a nutshell, the biting point is when the two clutch plates begin to make contact with each other as the clutch pedal is raised – the one connected to the engine then starts to try and push the one connected to the wheels round (i.e. the ideal position to hold the car balanced – not moving forward and not rolling back). You need to hold your foot still once you’ve found it – otherwise it isn’t a “point” and the car will not be in control. And also remember that all learners are different, so if you’re an instructor you may need to look for different ways of explaining it before it clicks with them.
There’s so much to remember
It might seem like that, but just think about when you first learnt to ride a bike, or took up any hobby or skill-based activity. Now, you don’t give a second thought to staying in the saddle, or playing the right chords, or hitting the ball cleanly with the bat. It becomes a habit. That’s what you want your clutch control to become – a habit. And it will become one quicker than you think… as long as you think positively.
I can’t find my biting point
Unless there is a fault with your car, yes you can.
The biting point is when the clutch plates just begin to engage with each other, and this is controlled by raising or lowering your foot on the clutch pedal to adjust the distance between the plates. You have to practice and develop finding the bite quickly.
If this question/problem arises due to switching between your instructor’s car and your own, it’s something you have to live with (or get fixed at a garage). All cars are different depending on age and adjustment (I remember having the clutch replaced in my own car some years ago – when I went to pick it up I couldn’t move it out of the garage to begin with as the bite was now much further down the pedal movement and I kept stalling it. It took a few hours driving to get used to it). It’s normal.
I couldn’t find the biting point in my car today
If you are a new driver (or a learner), sometimes in panic you might get your feet mixed up and not realise it. I know this sounds silly, but certainly in the early days I find many of my pupils can do that, and they are confused by what is happening until I explain what they were doing. I wouldn’t expect someone who is at test standard (or who has passed) to make this mistake, though.
Another possibility is that there is something wrong with your car. If your clutch is badly worn the two plates can slip and in that case nothing happens, so you wouldn’t be able to find the bite because there isn’t one! I know that from experience. Similarly, if the clutch fails completely – even with the pedal all the way up and the car in gear – there is no significant contact between the plates and nothing happens.
And another possible fault is that your clutch cable has snapped or is snagging somewhere. I’ve had both of those happen to me over the years – if the cable snaps the pedal usually just falls to the floor, but if it is just frayed due to friction it can catch on the cable guide which carries it.
Logically, it can only be the driver or the car which is at fault, so if you’re sure you were not doing something silly then there must be a genuine fault. Get it checked at the garage urgently – and don’t risk trying to drive it.
Will the car roll back when you have the biting point?
By definition, no. However, if you haven’t got enough bite then it might – just as too much bite will make it move forward.
You have to try to understand what the biting point is – and how it is part way between no engine control of the wheels at all and total engine control of the wheels. The exact point of bite varies depending on the angle of incline.
Do I need to keep my foot on the clutch when I have the biting point?
Yes, of course you do. If you understand how the clutch works from what I have explained above, then taking your foot off just means you don’t have the bite anymore. You take your foot off gently as you accelerate away, but if you want to keep the bite (for control at low speed, or if you’re waiting to move off) then your foot has to stay in control of it.
Taking your foot off quickly is almost guaranteed to end up either in a stall or a kangaroo-hop down the road. If nothing else, taking your foot off too quickly will result in a jerky move off.
How do I get the biting point in a left-hand drive vehicle?
It’s the same as I’ve explained above.