Key takeaways
Alignment is a system of angles, ride height and corner weights that work together, not a list of numbers to copy. Camber, toe and caster each trade grip, stability and tyre wear against one another. The reliable way to improve a track setup is to change one thing at a time, record it and let tyre temperatures and lap data tell you what happened.
A tyre only produces grip when its contact patch is working properly, and suspension geometry decides how well it does that as the car rolls, pitches and steers. Alignment is the process of setting the key angles so that the tyre stays in its best working range. The three you will hear about most are camber, toe and caster.
Camber: the lean of the wheel#
Camber is the angle of the wheel when viewed from the front. If the top of the wheel leans inwards towards the car it is negative camber. When a car corners, the body rolls and the outside tyre tends to lean over onto its outer shoulder. A little static negative camber compensates for that, keeping more of the tread flat on the road at the point of maximum cornering load.
Too little negative camber leaves the outer shoulder overloaded in corners. Too much reduces the contact patch in a straight line, which lengthens braking distances and increases wear on the inner edge. Typical road settings are mild, often well under two degrees negative, while track-focused cars on road-legal tyres commonly run more. The right figure depends on the car, the tyre and how stiff the springs and anti-roll bars are, so any range you read is a starting point, not a prescription.
Toe: where the wheels point#
Toe is the angle of the wheels relative to the direction of travel, as seen from above. Toe-in means the fronts of the wheels point slightly towards each other; toe-out means they point slightly apart. Because toe angles are small, they are usually quoted in millimetres across the tyre or in fractions of a degree.
At the front, a small amount of toe-out sharpens turn-in, because the inside wheel steers a little more than the outside one at the start of a corner, but it makes the car more nervous in a straight line. Toe-in does the opposite: calmer and more stable, slower to respond. At the rear, toe-in generally adds stability under power and in fast corners. Any toe angle that is not zero means the tyres are being dragged slightly sideways as the car moves, which scrubs the tread. Large errors wear tyres quickly, and a tyre that is feathered across the tread is a classic sign.
Caster: the steering axis tilt#
Caster is the backward tilt of the steering axis, seen from the side. It works like the trailing wheel on a shopping trolley: positive caster makes the wheels self-centre, adds steering weight and improves straight-line stability. As the wheel is steered, more caster also adds negative camber to the outside wheel and positive camber to the inside wheel, which helps the outside tyre in a corner. The cost is heavier steering. Caster is often only adjustable on some cars, and on many road cars it is set by the factory with limited ability to change.
| Setting | Increase or change | Grip | Tyre wear | Turn-in and stability |
|---|---|---|---|---|
| Front camber | More negative | Better cornering grip up to a point; less when upright | Inner edge wears faster if excessive | Sharper initial response |
| Rear camber | More negative | More lateral grip at the rear, less traction in a straight line | Inner edge wear | Can reduce stability if over-done |
| Front toe | Toe-out | Little direct change in peak grip | Faster wear with larger angles | Sharper turn-in, twitchier in a straight line |
| Front toe | Toe-in | Little direct change in peak grip | Faster wear with larger angles | Calmer, slower to turn in |
| Rear toe | Toe-in | Helps keep rear planted | Faster wear with larger angles | More stable under power and in fast corners |
| Caster | More positive | Helps the outside tyre when steered | Little direct effect | More self-centring, heavier steering |
Ride height and corner weights#
Camber, toe and caster are all measured at a particular ride height, and changing the ride height changes them. Lowering a car alters camber and toe through the suspension travel, and can also change roll behaviour. That is why the order matters: set ride height first, then alignment.
Corner weighting is the next layer. Each wheel carries a share of the car's weight, and on a track car you usually want the cross-weight, the combined weight on one diagonal pair such as front-left with rear-right, to be close to half the total so the car behaves similarly turning left and right. Weights are measured with scales under each wheel, with the driver or equivalent ballast aboard and the fuel level recorded, then adjusted using the spring perch height on coilover suspension. Adjusting one corner changes the others, so it is an iterative process.
Tip
Why alignment is a system, not a number
A camber figure that suits one car with stiff springs, wide tyres and a low centre of gravity may be wrong for another. Treat any published figure as a reference. The real answer comes from the car's behaviour, the tyre temperatures and the wear pattern. Always have the work done on a flat, level alignment rig, and repeat the checks after any change to ride height, springs or tyres.
A methodical track setup#
- Start from a known baseline: correct tyre pressures, a sound and healthy suspension (bushes, bearings, dampers), and a recorded alignment.
- Set ride height and corner weights first, then measure and set camber, toe and caster.
- Run a short session, then measure tyre temperatures immediately across the tread (inner, centre, outer) with a pyrometer, and record tyre pressures hot.
- Read the pattern. If the inner edge is much hotter than the outer, there is probably too much negative camber; if the outer is hotter, too little. An even spread across the tread, with the middle similar to the average of the edges, suggests the pressure and camber are about right.
- Change one thing only, by a small amount, and note it in writing along with the track temperature, tyre set and driver feedback.
- Repeat. If the lap time or feel does not improve, return to the previous setting and try a different variable.
Changing several things at once makes it impossible to know which one helped. A notebook or a logging sheet is as valuable as any tool in the workshop.
What this means in practice#
For a road car, alignment is mainly about tyre life, stability and predictable handling. For a track car, it is about holding the tyre in its working range under load, and that means testing. Use sensible starting points for your car and tyre, change one variable at a time, record everything and trust the evidence on the tyre. If you are unsure, ask a specialist to carry out the alignment and corner weighting, and work with them on the track setup rather than copying a figure from another car.
