Ralph Bossino

The three major alignment parameters; Camber, Caster, and Toe. Any car/track enthusiast should know these three terms and know them well as they play a major role in your handling characteristics.

CAMBER

Camber is the angle of the wheel relative to vertical as viewed from the front or rear of the car. If the wheel (top) leans in towards the chassis, it has negative camber; if it leans away from the chassis, it has positive camber.

The cornering force that a tyre can develop is highly depended on it’s angle relative to the road surface, and so wheel camber has a major effect on the road holding of a car. The more camber, the more tilt in the wheel, and the less contact patch on the ground in straight line traction. However, when going around turns, this levels out and gives you more contact patch which means more traction. (this is just explained very simply, it’s much more complicated and technical and many other factors also play a role.)

Many would think that optimal contact patch and in turn optimal traction would be gained with a 0 degree camber; however, this is wrong. Optimal would be around negative 1/2 degree. This is due to the contribution of camber thrust, which is an additional lateral force generated by elastic deformation between the contact of the tyre and road.

CASTER

Caster is the angle to which the steering pivot axis is tilted forward or rearward from vertical, as viewed from the side. If the pivot axis is tilted backwards (top pivot is positioned farther rearward than the bottom pivot), then the caster is positive; if it’s titled forward, then the caster is negative.

When you’re driving your car and for some odd reason it starts to pull to one side or the other, it means your caster is off. It is important to ensure that the caster is the same on both sides of the car to avoid the car from pulling to one side or the other. Positive caster ‘tends’ to straighten the wheel when the vehicle is traveling forward and is used for straight-line stability; however, greater caster angles cause an increase in steering effort.

TOE

Toe is … when a pair of wheels is set so that their leading edges are pointed towards each other or pointed away from each other. When their leading edges are pointed towards each other it is toe-in; when they are pointed away from each other, it is toe-out.

Toe is a very important part of any alignment. Many believe when they have uneven tyre wear, it’s due to the amount of camber one is running; however, this is completely wrong. The toe being off in relevance to the camber one is running is the cause of uneven tyre wear. Too much toe-in causes accelerated wear at the outboard edges of the tyres, while too much toe-out causes wear at the inboard edges.

Toe has three major areas of performance: tyre wear, straight-line stability and corner entry handling. While we learned that Camber has a hand in traction in the corners; Toe plays a part in the corner entry before the camber even takes it’s turn to help you in your corner.

CONCLUSION

Of course, none of these three things can alone make your car handle great, have great tyre wear, be stabilized around turns and in a straight-line; but all three of them working together in harmony with the right settings on each can do a world of goodness. And one must remember; when it comes to the track, these settings can vary drastically as opposed to daily street driving. When on a track; the settings should be geared to each individual as driving styles vary from person to person; and be geared to each individual track as every track is different.

… This is just a very brief description. It can get more in depth and more technical; but one must grab ahold of the concept of the three before dabbling into more specifics.