Clutch Biting Point
Your first few hours learning to drive in a manual car will probably be spent learning how to move off, stop the vehicle and change gears. All three of these tasks rely on the clutch pedal and learning how the clutch works, will be an important part of your early tuition. To understand how the clutch works, you first need to understand what the clutch biting point is. Once you have understood this, you then need to know how to find the point, what to do when you have found it and finally, what it should and should not be used for. Quick Navigation: Biting Point What is the Clutch Biting Point How to Find the Clutch Biting Point How can you tell if you are at the Clutch Biting Point When Should you use the Clutch Biting Point When Should you not use the Clutch Biting Point Clutch Biting Point in Petrol Cars and Diesel Cars Why should you read our guide? Here at Pass The Driving Test, we have literally taught thousands of hours worth of driving lessons and we understand in great detail, everything about the clutch and its biting point. We have written this guide to help students who are interested in learning about the biting point and those who are looking for advice, on how to find the biting point in petrol and diesel cars. What is the Clutch Biting Point The clutch is made up of two metal plates. The first plate is attached to the engine via a flywheel and this plate constantly rotates if the engine is on. This happens irrespective of whether the vehicle is moving or stationary. The second plate is attached to vehicle’s gearbox and wheels. When the two plates come into contact with one another, they begin to rotate at the same speed and a connection beween the vehicle’s engine, gearbox and wheels is formed. This connection allows power to flow between the three components, which in turn enables the vehicle to move. When the clutch pedal is up, the clutch plates engage and this allows the connection to be formed. At this point, if the vehicle is in gear, the clutch plates will lock together and spin in unison. When the clutch pedal is pushed down, the plates separate and the connection is broken. This break in the connection allows you to change gerars and stop the vehicle without the engine stalling. The clutch biting point is the point at which, the clutch plates first come into contact with one another. When the plates first meet, only a small perccentage of the vehicles powers is able to flow from the engine to its wheels. You can use the limited flow of power, to control the speed of the vehicle and this is known as clutch control Callout: Everything you need to know about clutch control How to Find The Clutch Biting Point The biting point is defined as the point at which the clutch plates first come into contact with one another. This point can differ between vehicles. Some vehicles have a low clutch biting point, while others have a high clutch biting point. To find your vehicle’s biting point, follow the steps below. Callout: Note:Before you start, make sure your you are in quiet industrial or residential area,, away from traffic and other road users Step 1: Turn the engine on Before starting the engine, ensure your seatbelt is on and the handbrake is applied. You can apply the handbrake by either pulling the centre lever located in between the driver and front passenger seat, or by pressing the parking brake button located on the vehicle’s console. Once you are sure the car is secure, turn the key in the ignition, or press the start button to turn the engine on. Callout: Some newer vehicles may require you to push the clutch pedal down to turn the engine on. If your vehicle operates in this way, push the clutch pedal down as you turn the key or as you push the start button Step 2: Push the clutch pedal down With the engine on, push the clutch pedal down as far as it will go. It is important to make sure the clutch pedal is fully depressed during this process. A partially engaged clutch will make it harder to find your vehicle’s biting point and could even lead to the vehicle stalling during the exercise Callout: If you find it difficult to push the clutch pedal down, adjusting the position of your seat could help Step 3: Select first gear With the engine on and the clutch pedal down, push the gear stick to the left and then up, to select first gear. You must be in gear to find the clutch biting point. The clutch plate attached to the gearbox will only rotate when the vehicle is in gear and two clutch plates will only engage when both are rotating. Step 4: Slowly raise the clutch pedal Slowly raise the clutch pedal, a millimetre at a time, until you feel the vehicle begin to strain against the handbrake. This is known as the vehicle’s biting point. On older cars with worn clutches, this point might be quite high up the cutch’s working travel. On newer diesel cars, the clutch biting point might be low, making it easier to find. Step 5: Keep your left foot still Once you have found your vehicle’s biting point, keep your left foot very still, as a sudden movement could cause the vehicle to stall when the handbrake is applied. Do you need to set the gas to find the biting point? You do not need to set the gas to find your vehicle’s biting point. The clutch will bite the moment the two clutch plates come into contact with one another. This happens independent of whether gas is applied or not. Gas is used to reduce the chances of the vehicle stalling and to help you move off quickly when the need arises Video: How to find your biting point without using the gas pedal How can you tell if you are at the clutch biting point? You will know if you have reached the clutch biting point when any of the following things happen; The sound of the engine changes As you try to find the clutch biting point, it is important to listen to the sound of your engine as you do so, When the clutch plates bite, the sound of the engine will change to a low rumble, which you could miss if you are not paying attention. The reason this happens is that when the clutch plates bite, the engine’s RPM drops, causing the sound the engine makes to change. The needle on the rev counter drops slightly Once the engine is switched on, the needle on rev counter will sit somewhere between 1,000 and 1,500 RPM. Once the clutch plates bite, the engine’s RPM drops and the needle on the rev counter will fall to around 1,000 RPM mark. The needle on the rev counter dropping in this way, is an indication that you have found the vehicle’s biting point. The front of the vehicle will lift up When your vehicle reaches its biting point, it will begin to strain against the handbrake. As it doe so, the nose of the vehicle will lift up and the car will begin to shake slightly. At this point, the clutch plates have engaged and the vehicle will move once the handbrake is released. When Should you use the Clutch Biting Point Once you have understood how to find the clutch biting point, it is important to understand when you should use it. Pulling Away You can use the clutch biting point to prevent the vehicle from stalling when pulling away on a level surface. By engaging the clutch and keeping your feet still at the biting point, the vehicle is unlikely to stall when the handbrake is released. Hill Starts The clutch biting point is extremely useful when moving off on a hill or upward slope. Engaging the clutch and balancing at the biting point, just before releasing the handbrake, should prevent the vehicle from rolling backwards. Callout: This guide will teach you everything you need to know about hill starts Emerging at busy junctions and roundabouts The clutch biting point can help you move off quickly when emerging at a busy junction or roundabout. You can increase the speed at which you move off, by applying gas, while at your vehicle’s biting point and quickly raising the clutch pedal, Driving manoeuvres The clutch biting point is also useful when completing any of the driving manoeuvres. When reversing, or manoeuvering the vehicle in tight spaces, it is important to move the vehicle at very low speeds. Instead of pressing the accelerator to do so, you can use the clutch biting point to evenly let in, small amounts of power, which should improve your control of the vehicle. When Should you not use the Clutch Biting Point Using the clutch biting point is an important part of driving a manual car. It can help prevent your vehicle from stalling and also help you to move off quickly. However, there is a downside to using it. Over time it can cause wear and tear on the clutch itself, causing the clutch to ‘slip’ and disengage without warning. The reason this happens is that at the vehicle’s biting point, when the two clutch plates first come into contact with one another, the plates touch but do not lock. At this point, they rub against each other and this rubbing motion can cause the friction on the plates to wear out. To avoid damaging your clutch pedal, avoid using the clutch biting point in the following situations; When Waiting on a hill or slope Avoid using the clutch biting point, to balance the vehicle when waiting on a hill or upward slope. Doing so may stop the vehicle from rolling back and allow you to move off quickly, however, it does cause excessive wear and tear on the entire clutch mechanism. While waiting, it is best to use the handbrake to secure the vehicle and only use the biting point once you are ready to move off again. When Travelling downhill When travelling downhill, some inexperienced drivers try to control the speed of the car using the clutch pedal. Not only is this wrong, but it is also dangerous too. A vehicle will speed up when travelling downhill, with the clutch pedal pushed down. It also leads to unnecessary wear and tear on the clutch itself. Instead of using the clutch, select a lower gear and use the brakes to reduce your vehicle's speed when travelling downhill, Clutch Biting Point in Petrol Cars and Diesel Cars The clutch biting point in a petrol car is similar to the biting point in a diesel car. Although the biting points may be similar, however, there is a difference between petrol and diesel cars when moving off. Diesel engines produce greater torque, or pulling power, at lower RPM. This greater pulling power, allows diesel cars to move off needing less of the clutch to be engaged before doing so. Petrol cars, on the other hand, produce less torque at the same RPM. This is why, when at the biting point in a petrol car, you may need to use the accelerator to avoid the vehicle stalling.
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