Whenever you get a new set of tyres, a technician will need to make some very precise adjustments to the way they are fitted. You may have heard of them resetting the "toe" angle and wonder what that can refer to. Why is this one of the most important adjustments the mechanic can make, and how can it affect your car's handling if it's not performed correctly?
Understanding the Angles
The toe angle refers to the wheel's position in relation to the centreline of the vehicle. It can be further defined as either "toe-in" or "toe-out", according to whether the front of the wheel tilts toward the centreline or away from it.
Handling and Tyre Wear
It can be almost impossible to see any difference with the naked eye, but if the toe angle is not adjusted correctly, it can certainly affect the vehicle's handling and directional stability. While the adjustment may only be fractional, it is crucial if you want those new tyres to last as long as possible without patchy degradation.
How Adjustments Are Made
To adjust the toe angle, a mechanic will first need to loosen the bolts on the end of each tie rod. These rods connect the wheel to the steering column, and the bolt will be rolled backwards or forwards on the threaded rod. Small adjustments can make the difference between neutral, in or out, and the technician will often use a computerised alignment tool to help get everything right.
In most cases, your vehicle will be configured so that it has a tiny amount of toe-in. This is generally considered to be the most stable situation when driving at speed and can give the motorist more control without a tendency to wander in a straight line.
In even more technical terms, this type of configuration can cause a vehicle to understeer when going around a corner. This is a slight tendency for the front of the vehicle to push towards the inside of the bend. If the car has more toe-out, then the opposite would be true, leading to oversteer. Here, the rear of the car would trend towards the inside of the bend instead.
Getting It Right
Most motorists do not need to worry about oversteer or understeer but should be more concerned with general handling and excess tyre wear. Thankfully, the technician is trained to get this right and so you should always ensure that your wheels are aligned after a new tyre purchase.
Contact a tyre alignment service to learn more.