It is the angle between the pivot line (in a car an imaginary line that runs through the center of the upper ball joint to the center of the lower ball joint) and vertical. The front steering forks on a motorcycle are an easy-to-see example of how caster works. The firm and stable steering provides the driver with confidence and allows them to drive at higher straight-line speeds as they are not fighting the steering wheel. That’s because vehicles with power steering tend to have a positive caster, and vehicles without power steering typically have a negative caster. Also, zero caster provides easy steering input without the extreme instability of using negative caster. The caster angle is determined by your vehicle’s suspension design and the intended vehicle use. Steering is slightly easier than positive caster and marginally harder than a negative caster. Adam has 8 years experience as a mechanic, working on hybrids, diesels and gas-powered vehicles. Caster, which is also referred to as caster angle, is the top to bottom angle of the steering axis and suspension components as they meet the wheel. A zero caster isn’t bad, but it doesn’t do anything to improve performance either. Weather changes drastically alter your tire pressure, and unless you’re keeping an eye on it, you’re losing traction every time you step in your vehicle. In simpler words – picture the side of a vehicle, now imagine a vertical axis (line) that runs straight through the center of your front wheels. Our mission is to help you modify your car the right way, whatever your budget. For modern vehicles however, power steering has made that advantage obsolete. Making any changes beyond a few degrees would require a significant overhaul of your suspension system, and this isn’t a common way to alter your vehicle, so you’ll likely end up needing some aftermarket parts. Caster angle refers to the location of your vehicle’s upper ball joint or strut mount compared to the lower ball joint. A good example of extreme caster angle would be the front suspension on a chopper motorcycle. How to Adjust. Historic and class cars had negative caster, which made their non-powered steering systems much lighter. However, the method that the cart uses (displacement caster) is different than how your … It basically means you won’t have to turn the wheel as often to correct for divots and bumps in the road. This angle evaluates the back and forth incline of the axis. Camber is the angle or tilt of the tire viewed from the front or rear of the vehicle. Positive caster angle: the self-aligning torque. Caster angle definition: the forward or backward tilt of the steering axis in a vehicle, when considered from the... | Meaning, pronunciation, translations and examples Primarily because most mods that are popular on a Jeep involve the suspension. The only notable advantage to having negative caster is that the steering input effort required is very low making the steering very easy to turn. This effect causes the outside wheel in a turn to gain negative camber, while the inside wheel gains positive camber. Caster affects a vehicles resistance to turning, and changes the amount of camber gain a wheel has when turned. L'ensemble de roulettes (302) comporte un dispositif de blocage pour roulettes (604) à un certain angle par rapport au plan de la planche. This is an angle that can be measured and adjusted, following a four wheel alignment check on your car. You can add or remove shims from the rear bolt or where the upper control arm attaches to the hub. 1,747 Posts . The caster angle is the angular displacement of the steering axis from the vertical axis of a steered wheel in a vehicle measured in the longitudinal direction. The only downside to positive caster is that it increases the effort it takes to steer your vehicle. Smack right in the middle of positive and negative caster is the compromise — zero caster. Cross camber may also be specified, but not usually both. Discussion Starter • #1 • Mar 21, 2012. Camber angle could be either positive or negative depending on the design of the chassis and suspension system. The advantages of positive caster angle on a race car. A negative camber angle will result in tire wear on the inside of the tire. Can we get a vrooom over here? Wanting safer, cheaper and smoother motoring? One advantage of using zero caster is that it retains the slight reduction in kingpin torque before reaching the limit of adhesion, which is useful for a driver to know when the limit is near. Castor or Caster angle . The angle between the drawn line and vertical is the caster angle. The caster angle is the angular displacement of the steering axis from the vertical axis of a steered wheel in a vehicle measured in the longitudinal direction. Power steering is usually necessary to overcome the jacking effect from the high caster angle. Wider wheels in the rear of your vehicle will give you more traction when both braking and accelerating. Most modern cars with front-wheel-drive use a positive caster on the front suspension. If the vehicle has power steering, they opt for positive caster, and if they don’t, they use negative caster — it’s just that simple. These camber changes are generally favorable for cornering, although it is possible to overdo it. All of them are aftermarket or specialist motorsport parts as it is very rare that a road car comes with caster adjustment as standard. In fact, it can lead to significant performance concerns. A simplified way to think of it is the angle of the ball joints. We may be given a small commission when you purchase a product from our site. Vehicles with negative caster suffer from reduced stability and poor handling. Camber is positive (+) when the top of the wheel leans outwards (away from the car) while it is negative (-) when it leans inwards (towards the car) at the top. There’s simply no need for a vehicle with a zero caster. In simpler words - picture the side of a vehicle, now imagine a vertical axis (line) that runs straight through the center of your front wheels. Did you miss the lessons about camber and toe? In the automotive field, negative caster gives no feedback to the driver in terms of wheel position. Whether you’re heading to the track or the highway, these are advantages you want on your vehicle. Negative caster would help with this. De très nombreux exemples de phrases traduites contenant "caster angle" – Dictionnaire français-anglais et moteur de recherche de traductions françaises. It’s the pivot angle of the front wheels measured from vertical, when viewed from the side. Caster. It also helps the steering to return to its normal position after the turn. Can you detect a caster problem on your own? The caster assembly (302) has a caster pin (604) at an angle with respect to the board plane. So, focused on racing cars and on positive camber, we can resume the two primary benefits: When cornering, the vehicle weight shift is met with a maximization of the tire contact patch on the outside front wheel that’s under maximum cornering load. Wheel Alignment: Caster Angle. Your email address will not be published. The caster is one of the key parameters of the front axle: this is the angle formed by the axis of the bolt that connects the stub axles to the C of the chassis relative to a hypothetical axis perpendicular to the ground. The most common way to adjust your caster angle involves adding or removing shims to obtain the proper angle. It doesn’t make much sense without a little context — how can a tire tilt from front to rear since it’s a circle? Sometimes. We continue our journey in the world of tyres and suspension: caster. Zero caster is when your upper ball joint or strut mount is directly in line with the lower ball joint. So today we are talking about Caster. Caster angle settings affect the following: Steering Effort - Increasing the amount of positive caster will make turning the wheel more difficult. This is called cross caster and the difference is called the spread. Ever been in an old car that has very heavy steering? Jeep caster angle (also "castor" angle) is one of those things you'll come across a lot. Just know that any significant upgrades to your vehicle’s engine will need you to tune your vehicle to prevent engine damage. In performance driving circles a caster increase – sometimes to the maximum available setting that the vehicle will accommodate – is credited with improvements in vehicle handling, maximum traction, and steering responsiveness. Caster and Camber Angles. The angle between a line drawn from the car suspension strut to the ground (pivot point) and the tyre contact point. No matter what you do, chances are, there's going to be a front end, or 4-way alignment involved at the end. They run a large amount of positive caster to make the cart track straight without wandering. Even if your power steering fails, modern vehicles are incredibly difficult to drive without power steering, regardless of the caster angle. Another way to improve performance is with the help of a staggered wheelset. A Guide to Positive, Negative & Zero Scrub Radius, Other Ways to Improve Performance and Handling. But everything gets a little clearer when you realize we’re talking about the upper and lower mounting of the hub assembly in relation to your tire. While camber is the side-to-side tilt of your tire, caster, also known as “mechanical trail” is the front to rear positioning. In this guide, we break down everything there is to know about caster angle, it’s different types and the various handling effects it has on your car. When it comes to positive caster, there’s nothing to not love. However with power steering systems this is not an issue. You should never intentionally adjust your car’s suspension in a way that gives it a negative caster angle. It is also the type of caster that is used on a shopping trolley (or hospital beds, office chairs…) and is the reason why wheels can wobble and turn easily. Just remember, positive caster is a positive thing while negative caster is a negative thing. For a kart, which has no differential on the rear axle, the caster is a key factor which determines different aspects of the set-up. Disadvantages of a negative caster angle. What is Caster Angle? If it doesn’t, your vehicle has either damage or wear to the suspension components. Caster, also known as the caster angle, is the slant measured from the top of steering axis to the bottom of the wheel when the former is attached to the latter. Furthermore, performance upgrades, like aftermarket turbos, intakes, and exhaust systems, are great ways to improve your vehicle. Remember, adjusting your caster angle will adjust the camber too, so make sure to readjust the camber angle afterward. When the upper ball joint or strut mount is more towards the vehicle’s front than the lower ball joint, the vehicle has a negative caster. The only advantage to negative caster is that it’s easier to turn the steering wheel. This is measured by drawing a line between the top and bottom pivot points of the front upright. Stability - More positive caster stabilizes the wheel at speed. Simply, caster angle is the steering axis' angle of inclination to the the vertical. Casters are used in numerous applications, including shopping carts, office chairs, hospital beds, and material handling equipment. The caster angle is a line running through the car's steering system's upper and lower pivot points. This self-aligning torque also pulls the wheels back to a straight line when exiting a corner allowing the driver to be much smoother on corner exit, controlling the rate that the wheels return to center. If the pivot axis is tilted backward (that is, the top pivot is positioned farther rearward than the bottom pivot), then the caster is positive; if it’s tilted forward, then the caster is negative. Caster is the measure of how far forward or behind the steering axis is to the vertical axis, viewed from the side. The camber angle is measured in degrees. While camber gets all the attention, a more effective way to tighten up the handling of your car is to adjust it’s caster angle. An example of caster in action is the front wheels on a shopping cart. The angle made by the vehicle's wheels against the vertical axis is called Camber. Excessive caster angle will make the steering heavier and less responsive. Positive caster improves your vehicle’s responsiveness when rounding corners and improves your vehicle’s stability when traveling at higher speeds. Caster angles over 7 degrees with radial tires are common. A zero camber setting is best for going in a straight line. Vehicles with SLA suspensions use the upper and lower ball joints to create the angle, and those with struts use the center of the … It’s also incredibly rare. But since almost every modern vehicle comes equipped with power steering, you’ll barely notice the difference. If you’re looking for a cheap way to get a little more out of your car, adjusting your caster angle might be just what you need. Keep in mind that while this method will allow you to change the caster angle by a few degrees, you won’t be able to turn a negative caster into a positive caster or vice versa. There a few ways that caster can be adjusted on car. There are several advantages to a vehicle with a positive caster — these include increased steering angles and better straight-line tracking. Required fields are marked *. The result will be a vehicle with less traction and poor handling. Or maybe you’re trying to figure out why your vehicle isn’t handling right after that last tire change and don’t want to spend a ton of money trying to improve it. It’s genuinely the in-between for negative and positive caster in just about every way. Now it’s the time for Caster to be analyzed. As long as your vehicle has power steering, and unless you drive a Model T or other antique vehicle, there are no disadvantages to positive caster. Wheel alignment the ‘essential […] However, for vehicles with power steering systems, this is not really an issue. Caster is the forward or backward tilt of the steering axis viewed from the side of the vehicle. The angle between these two lines is the caster angle of that wheel. But what is caster angle, and how does it affect your ride? Caster influence on Camber angle: the turn condition. Caster and camber angle relation on car performance. We can state that caster angles over 7 degrees with radial tires are common. Because of this, you’ll typically find negative caster in older vehicles with outdated steering systems. Caster refers to the angle that is created by the steering pivot point in relation to the front and the back of the car. As an Amazon Associate we earn from qualifying purchases. Caster is positive if the line is angled forward, and negative if backward. While zero caster is better than negative caster in modern vehicles, it’s far from perfect. Firstly, it’s important to note that you can’t always adjust your car’s caster, especially in front-wheel drive vehicles. The main disadvantage to positive caster is that the steering requires a higher amount of input effort to turn the wheel. Caster angle refers to the location of your vehicle’s upper ball joint or strut mount compared to the lower ball joint. A vehicle's camber affects tire wear and stability. Un angle de chasse excessif rendra la conduite plus rigide et moins sensible. If you have a high speed, high performance ride, your sports car will need more caster to handle better on the straightaway and when coming out of turns. Because of this, there isn’t much need for vehicles with zero caster. They point forward at the bottom and slope back at the top, causing the tire to remain stable. What is the Caster Angle? The rear suspension on … What is the OME caster angle? What to read more about tyres and suspension: caster? Positive Caster If your upper ball joint or strut mount is located more toward your vehicle’s rear than the lower ball joint, your vehicle has a positive caster. Positive Caster: axis of rotation and contact patch. As you may have guessed, negative caster is the exact opposite of positive caster. A Quick Summary of Caster Angle: Keep it Positive. But unless you have a vehicle without power steering, you won’t even notice the difference. Caster angles over 10 degrees with radial tires are common. If your upper ball joint or strut mount is located more toward your vehicle’s rear than the lower ball joint, your vehicle has a positive caster. So keep it positive! A further disadvantage of negative caster is that it will increase under braking conditions making the steering more unstable (the so called “caster flutter”) due to the car pitching forward. These are eccentric bolts that can change your angle by a few degrees. Fortunately, most modern vehicles have power steering abilities which reduce the heaviness felt in the steering wheel whenever you have a positive caster angle on your wheels. While a positive caster has several advantages, there are no advantages to a negative caster in modern vehicles. Check our related articles below! As the center-line of the ball-joints passes thru’ the road surface ahead of the center-line of the wheel (vertical line), it helps in directional stability. Find them out in our mechanical lessons! If your car doesn’t provide a way for you to adjust the caster independently, your only hope is to adjust the camber and hope that it shifts the caster to spec. Power steering is usually necessary to overcome the jacking effect from the high caster angle. A final change you can make to improve your vehicle’s handling is to keep an eye on your vehicle’s tire pressure. Your email address will not be published. What is caster angle | F1 setup and performance, The meaning of tire code explained | Motorsport World, Modeling the Tyre Behaviour: Magic Formula and Brush Tyre Model, Modeling the Tyre Behaviour: g-g diagram, mechanical and…, Toe definition: 3 things you don't know about toe alignment, Why camber angle influences car dynamics | Suspension F1, © Copyright - presticebdt - F1 & Anime World, Toe definition: 3 things you don’t know about toe alignment, The caster angle explained and its influence in Motorsport. (The real caster is zero because the wheel patch is simply offset from the vertical and there is no relative angle between the steering axis and vertical, but we can compare this example to a wheel with negative camber for the position of the pivot). Caster is the measure of how far forward or behind the steering axis is to the verticle axis, viewed from the side. Some front-end alignment calls for different right side and left side caster. However, some vehicles do have ways for you to adjust the caster angle. Traductions en contexte de "caster angle" en anglais-français avec Reverso Context : Excessive caster angle will make the steering heavier and less responsive. Camber and caster adjustment bolts are a possible option. This effect is best visualized by imagining the unrealistically extreme case where the steering axis would be horizontal-as the steering wheel is turned, the road wheel would simply change camber rather than direction.