What Are the Positive and Negative Caster Angle Effects? - AllCarIndex
Vehicle alignment or wheel alignment is an important aspect of car maintenance. A proper wheel alignment ensures the tires meet the road at the proper angle. According to experts, right wheel alignment means the tires are centered in the wheel wells and straight.
You need to always align wheels to original specifications for the most extended tire life, good gas mileage, proper road contact, and smooth ride. Of all the wheel alignments, the caster is least known. Without a caster, all vehicles will be less stable. Here is some important information about the caster and positive and negative caster angle.
What Is Caster?
The vehicle's suspension geometry consists of three crucial measurements- toe, camber, and caster. Caster refers to the measurement on the steering wheels (the front wheels). It refers to an angle that measures the backward and forward tilt of the tilt axis when looking at the vehicle from the side.
The axis connects the upper and lower pivot joint. The angle is formed by the vertical line that goes through the lower pivot joint. If you ask any car mechanic about a caster, they will mostly talk about positive and negative caster angle.
What Is a Negative Caster?
In the negative caster, the lower pivot point is positioned behind the upper pivot point. The pivot arrangement results in a tire contact patch hitting the ground behind the steering wheel's position and suspension. The axis slants back to the central axis towards the vehicle's front.
What Are Negative Caster Effects?
The negative caster was a classic technology when there was no power steering available. Automakers added a negative caster to make the steering feel lighter feel for drivers. The negative caster is not used in modern cars. The straight-line stability and the self-aligning torque characteristics are absent in the negative caster. The negative caster setup is not considered acceptable as it could result in greater front wheel instability.
The modern car's internal chassis and structure do not support a negative caster. The negative caster also had problems with stability, and the steering became too light. Due to these characteristics, some drivers still like to have a negative caster angle on their wheels.
What Is a Positive Caster?
In the positive caster, the lower pivot point is in front of the upper pivot point. The pivot arrangement results in a tire contact patch hitting the ground in front of the steering wheel and suspension. In a positive caster, the steering axis appears at a slanting position in front of the vertical axis.
If you look closely at the steering axis, it slants in the front at the bottom of the vertical axis while the upper end of the steering axis slants backward of the vertical axis.
What Are the Positive Caster Effects?
You will notice the effect of a positive caster when driving forward. The vast torque straightens the steering wheel that leads to increased stability as you move ahead. If the positive caster angle is increased, it will cause steering heaviness.
Benefits of Positive Caster
- Improved Straight –Line Stability
The forward positioning of the wheel produces a self-aligning torque. It is a challenging engineering concept to explain. However, the idea behind this is the positive caster angle generates a tension that keeps the wheels pointed straight ahead while driving the car at speed.
- Improved Cornering Performance
Caster has a direct relation to the tire's ground contact patch. Positive caster maximizes tire contact patch while cornering. It leads to maximizing the tire grip.
Important Things to Consider While Altering the Caster Angle of the Car.
If you desire to change the car's caster angles, make sure all caster angles are completely symmetrically to each other. If you miscalculate the caster angles, you will experience a car pulling towards one side or the other. The car will pull towards the side, which has a lower caster angle.
To sum up, the caster angle is an essential factor in your vehicle's stability and performance. If you want to experiment and find out which caster angle works best for your car, consult a professional before making any changes.