Car servicing: Wheel balancing

Today we're talking about a vital service that many people overlook or just don't know about when having new tyres fitted to their car, it's called wheel balancing and it's something that every vehicle can benefit from. You can usually tell when your wheels are out of balance when you begin to feel a judder through the steering wheel above certain speeds.

When you look at a wheel, most of the time it appears to be perfectly symmetrical but there are in fact tiny imbalances all over the place that you simply wouldn't notice. These imbalances range from an innocent valve stem hole to a slight distortion in the wheel, or even in how the tyre has been applied. These imbalances are almost unavoidable, especially when a car is a few years old and has seen a fair bit of action on the roads.

At slow speeds this imbalance isn't a huge issue but as the wheels spin faster and faster, these small imbalances are amplified by centrifugal force and begin to have a negative effect on the balance of the wheels - this in turn causes vibrations & uneven tyre wear, as well as putting stress on your wheel bearings and suspension system. For every extra wheel that's poorly balanced, even more unnecessary stress will occur. 

Luckily, there's a very simple fix for all this. Good old fashioned weights. If you've ever looked at the back of a wheel, you may have noticed these weights. There are generally two types of wheel weight; Bang on weights which are used for steel wheels and clip onto the edge of the rim and adhesive weights which are usually found on alloy wheels - They are preferred over bang on weights as they are less likely to disrupt the alloys lacquer and lead to corrosion (which usually isn't a problem with steel rims). These weights are made to measure for each wheel and designed to counteract any imbalances that may have occurred. With the correct balance, there should be no negative effect from centrifugal force with uneven tyre wear and vibration problems a distant memory. 

To make sure the wheels are completely balanced, we use a machine that spins up each wheel (with the tyres on) to a relatively high speed and detects any light or heavy spots in the wheel to determine the exact nature of any imbalances. The machine then gives our technicians a readout telling them how much weight to use to remedy the problem as well as where to place it. Wheel balance will by it's nature slowly change over time and so it's important to make sure wheels are balanced whenever possible, for this reason we will always look to rebalance a wheel when a tyre is removed and replaced during servicing or maintenance.

So, that's the basics of wheel balancing - We hope you've learned a little more about what we do today as well as why wheel balance is so important.