A Brief Guide to Wheel Balancing
Wheel balancing, sometimes referred to as tyre balancing, is the process by which the weight of the wheel and tyre combo is equalized for smooth rotation at high speeds. Balancing entails putting the assembled wheel and tyre on a balancer that centres the wheel and turns it to decide on the proper weight placement.
An Imperfect Science
4×4 steel rims and tyres are never the same weight all around. The valve stem opening typically takes a small weight from that side of the rim. Tyres often have slightly imbalanced weights, whether they come from a cap ply joining point or a slight out-of-round condition. At highway speeds, a slight weight imbalance can bring a significant centrifugal force imbalance, which causes the wheel and tyre to spin in a lopsided fashion. This usually leaves the driver with a noticeable vibration as well as damaging and abnormal tyre wear.
To balance tyres and Fuel wheels, a balancing machine is used. There are ways to balance tyres manually, but they don’t really compare to machine balancing in terms of simplicity or accuracy. The wheel is mounted to the balancer spindle via the centre bore, and a cone is used to ensure that the wheel is properly centred. The assembly is spun at high speeds to find the heaviest point, and the results tell the operator how and where to place weights on the wheel’s opposite side.
Things to Know About Balancing
- It’s necessary. Wheel and tyre imbalances are almost inevitable, and it’s rare to see a wheel and tyre combo come out perfectly balanced from the factory. Whether or not the results are favorable, it’s important to have wheels and tyres tested for proper balancing.
- Wheel and tyre balance changes with time. As tyres wear out, the balance may slowly change. Most tyre shops will rebalance tyres when they’re rotated, or when seasonal tyres are swapped out. If tyres are rebalanced at least once during their lives, that lifetime will undoubtedly be longer.
- It only resolves balance issues. A tyre rebalancing won’t prevent vibrations from a bent rim, out-of-round tyre or abnormal wear pattern. The weights can’t compensate for physical issues, they can only help with weight differences.
Road Force Balancers
Because abnormal wear and vibrations have causes other than balance, the road force balancer came into use. This type of balancer, along with a conventional spin balancer, can measure the tyre and wheel to determine whether there’s a condition that can cause vibration during driving.
The solution here is to measure the tyre and wheel, and then to move the tyre around until its high spot matches the wheel’s low spot, in a process known as match mounting. Most of today’s tyres have dots on their sidewalls to indicate the point that should line up with the valve stem. Here, road force balancing machines do a precise job by measuring both the tyre and the wheel with rollers, and directing the machine’s operator to mark the match points. The resulting combo requires less balancing weight and it will spin straighter.
Adhesive vs. Bang-on Weights
In the early days of tyre balancing, bang-on weights were used. These lead weights came in various sizes, and included a soft flange that was knocked onto the wheel edge with a hammer. With steel wheels, these weights were very useful. However, with the advent of alloys, problems arose as bang-on weights broke the clearcoat and caused wheels to corrode. Adhesive weights have a sticky backing, and they can be cut to size and stuck to the inner barrel behind the wheel’s spokes. While the adhesive is very strong, a good tyre tech will clean the surface as much as possible before applying the weights.
When you buy wheels, a Ford Ranger grill Raptor and Toyota Hilux accessories from a 4×4 online superstore and take the wheels and tyres for mounting, ask for adhesive weights during the balancing process. Be wary of any tyre shop that doesn’t use adhesive weights; many shops will use bang-on weights on the inside as a way to cut costs. This is OK unless you’ve got chrome wheels, where any rupture in the surface of the chrome can lead to damage.
There you have it—the science of tyre balancing. If you need to know more about wheels and tyres, or you need help choosing from the best 4×4 lift kits, visit an online shop today.