Alternative Springs

Coil springs and leaf springs are the two most common type of spring within the automotive and motorsport industries. However, other types of spring have been tried and tested in an attempt to get the edge over competitors. Some of the following springs are still used within motorsport today. Torsion Bars Torsion bar springs work […]

Coil Springs

What is a coil spring? A coil springs is a piece of bar that has been twisted to form the shape of a helix (spiral). It works in an up and down motion as a spring by using the vertical displacement to twist the bar making the spring. Therefore, it is effectively a torsion bar […]

Anti-Roll Bars

What is an Anti-roll bar? An anti-roll bar is a tube of metal that works as a spring between left and right wheels. An anti-roll bar connects the vertical motions of the left and right wheels and works in parallel with the coil springs. During cornering, the outside wheel (be it front or rear) wants […]

Dampers

What is a Damper? A damper is an oil filled tube with a piston inside. The piston moves through the oil, passing the oil through small precise holes and past a sprung shim, at a certain designed speed. Damper Construction A damper consists of: A main body A piston with precisely machined holes through it […]

Tyre Slip Angle

What Is Slip Angle? A slip angle is the difference between the steering angle and the direction in which the tyre footprint is taking. Tyre slip angles play a major part in steering systems and have a large effect on aspects of steering geometry such as Ackermann and toe. When a tyre runs at slip angle, […]

Toe

What Is Toe? Toe is the angle between each wheel with relation to the longitudinal axis of the vehicle. It is usually measured when the car is static and is measured either in degrees or in millimetres. If it is measured by distance then it is usually the difference in distance between the two rear […]

Scrub Radius

What Is Scrub Radius? When viewing a wheel from front view, the scrub radius is the distance between where the extrapolated line of kingpin axis touches the road and the tyre contact patch centre point. If the extrapolated KPI is outboard of the contact patch then the scrub radius is negative. If it is inboard […]

King Pin Inclination

On current suspension systems, the kingpin is set at an angle to the vertical plane when viewed from the front or rear of the vehicle. This angle is known as the king pin inclination. The purpose of the KPI is to produce vertical displacement of the vehicle in during steering in an upward direction. The larger the KPI, the larger the effect. This lifting effect produces a self centering torque similar to that of caster. The KPI also generates scrub radius.

Instantaneous Centre

What Is An Instant Centre? The word “instant” means at that particular position of the linkage. “Centre” refers to a projected imaginary point that is effectively the pivot point of the linkage at that instant. The instant centre is a point in space, governed by the position, angle and length of the upper and lower […]

Grip

What Is Grip? Grip, put basically, is the force generated between the tyre and the surface. The amount of grip generated and maintained is influenced heavily by the mass of the vehicle; the acceleration of the vehicle, the compound of the tyre, the compound of the road surface and by the suspension geometry of the […]

Front View Swing Arm

What is Front View Swing Arm (FVSA)? The front view swing arm (FVSA) instant centre location controls the roll centre height, the camber change rate and the tyre lateral scrub. The instant centre can be located inboard of the wheel or outboard of the wheel. It can be above ground level or below ground level. […]

Caster

What Is Caster? Caster is the measure of how far forward or behind the steering axis is to the vertical axis, viewed from the side. This is measured by drawing a line between the top and bottom pivot points of the front upright. The angle between the drawn line and vertical is the caster angle. […]

Camber Gain

What Is Camber Gain? Camber gain is the change in camber angle per amount of vertical displacement of the wheel. The most common situation is that camber will become more negative if the wheel is moved vertically upwards. Likewise, the wheel camber will become more positive if the wheel is moved vertically downwards. Camber gain […]

Camber

What Is Camber & What’s Its Purpose? Camber angle is the angle between the plane of a wheel and the vertical. It is described as positive when the top of the wheel leans outward and negative when the top of the wheel leans inward. Camber angle alters the handling characteristics of a suspension system.

Bump Steer

What Is Bump Steer? Bump steer is a change in the steering angle of the wheel when the wheel is in bump or droop without turning of the steering wheel or lateral movement in the steering rack. This is due to the arc patterns of the wishbones and the steering arm having different radii and […]

Suspension Systems

Types of Suspension Systems There are many types of suspension systems used within motorsport; the most common being a spring and damper set up. The popularity of the spring and damper set up is mostly due to its compact size and its easy, fast and direct tune-ability. There are multiple ways of using a spring […]

Ackermann

Ackermann Steering Geometry In order for a car to turn smoothly, the inside wheel must travel on a smaller radii arc than the outer wheel. This is achieved by the inside wheel turning more than the outside wheel. This concept is known as Ackermann steering geometry. Perfect Ackermann geometry can be devised using the wheel […]