Wheel Alignment | Tyre Balancing
Wheel Alignment and Tyre Balancing are pivotal for ensuring optimum grip for the safety of the driver and passengers, along with preservation of vehicle components and tires. Wheel Alignment plays a major role in the safety of the vehicle and how the vehicle drives. Specialised equipment is used to adjust the vehicles suspensions and the way the tyres make contact on the road. Misalignment can occur for several reasons, but first, it is important to understand how Wheel Alignments work and its components.
3 Main Components:
Camber angle is the discrepancy of a wheel and how it sits. Tyres are generally known to sit flat with the surface of the wheel touching the road with no extra angle. When the vehicle has the ideal contact patch with the road, it is sitting at 0 degrees. Wheel Alignments aim to correct camber angles by adjusting the suspension accordingly. If the top of the wheel is leaning at an angle that is clockwise, it is known as Negative Camber.
Negative Camber creates what is called “Camber Thrust”. The safety concern and drawback to performance for Negative Wheel camber is feedback to the driver through the handling output. Track cars and spirited drivers may add Negative Camber to their vehicle as it provides increased grip through heavy and fast cornering, however, the contact patch between the tyre and the road is minimised when driving straight and accelerating, which is why proper Wheel Tracking is vital.
The concept behind Camber Thrust is when a tyre loses traction, the vehicle is thrust in the direction of the wheel that has lost traction. E.g. if the front two tyres have Negative Camber and the driver’s side wheel loses traction, the entire vehicle will thrust towards the Driver’s side of the vehicle – a huge safety concern which could cause an accident, which is why Wheel Alignment is crucial.
If both tyres are constantly in contact with the road, it is drivable and vehicle owners often use it for its aesthetic appeal, however, issues arise once traction is lost, which can be unpredictable.
Zero Camber can wear your tyres evenly, but cornering performance can be sacrificed. Daily driving and road driving are ideal for driving with Zero Camber as users don’t require heavy cornering performance at high speeds. Wheel Alignments are important as they can be fine-tuned to driving styles and the conditions in which the vehicle is driven. Wheel Tracking can be set up to improve a tyre’s lifespan.
Positive Camber is limited on a vehicle as the angle of the wheel would be rotated anti-clockwise, meaning the vehicle would contact the guards and the wheel well. Drivers are constricted by the constraints of the vehicle when applying Positive Camber.
Caster is used to improve directional stability, better handling performance and reduces excessive tire wear. The defining factor of caster is dictated by the steering axis of the vehicle and is measured in Degrees. If a Steering Axis is vertical, it is at zero degrees caster.
When tilted rearward, it is known as positive and alternatively, negative camber is when the steering axis is tilted forward. It is crucial to find the ideal setup for Wheel Tracking as it can increase stability at high speeds and can provide added tire lean when cornering but can also increase the steering effort required.
Toe is when the angle of the tires is pointing inwards or outwards. A great way to conceptualise this is if someone is standing up and looks directly at their feet. If they tilt their feet inwards to the point where their front toes are touching, it is known positive Toe.
This creates a constant force generated against each other which reduces turning and handling ability, however it can improve straight line performance. Negative Toe is when both wheels are angled in the opposite direction to one another.
This can increase cornering stability as the tires are angled aggressively when turning, meaning the radius the wheel must travel is much lower. Straight line performance is impacted as a result and any change in directions will cause the car to head in the opposite direction.
A correct Wheel Alignment on a vehicle will ensure the tires will wear evenly and extend tyre life. Toe in either direction will cause the tyre to scrub against the surface of the road rather than have an ideal contact patch and will wear the edges of tires much quicker. It can be beneficial for track use and motorsport; however, it is not ideal for driving on public roads.
Tire Balancing is a process that is usually conducted in the Wheel Alignment process or when purchasing new tyres, wheels or both. There are two main types of Tire Imbalances that Wheel Alignment and Tire Balancing can correct – Static & Dynamic.
Drivers can also have their tire balanced if they’re noticing uncontrollable steering output and the vehicle is veering without the driver’s input. Tire Balancing refers to the compensation of weight imbalances and discrepancies of the wheel and tire combination the user has selected.
Static tire balancing addresses the issues on a vertical movement which can cause vibrations in the steering input. Dynamic imbalances address vertical and lateral movement. Both balancing techniques require specialised equipment to identify and balance tires properly.
Tire Balancing is usually conducted during the Wheel Alignment process when the tire is placed on a Wheel Balancing machine once the wheel and tire combination is put together. Each tire goes on the bore of the balancing machine and spins rapidly.
A laser measures the balance and shows any discrepancies. A laser guides the technician on where the weights need to place and how many. Correct Tire Balancing and Wheel tracking prevents premature tread wear and should be aligned every 8-10 000km and can help maximise the lifespan and performance of tyres.