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1.
The definition of balance is the uniform distribution of mass about an axis of rotation, where the center of gravity is in the
same location as the center of rotation.
2.
One of the limitations of balancing tire and wheel assemblies off a vehicle is that repeatability can be an issue. In other
words, you may not get the same results when you attempt to rebalance a wheel that has already been balanced. What has
changed? It is not the tire or rim. What has changed is the geometry of the tire and wheel on the balancer.
3.
Weights on the wheel have an inherent problem due to the tire/rim geometry. Since the imbalance is normally out at the
tire tread surface, and has more effect on balance than an equal weight located at the rim radius.
4.
Wheel balancers operate at a smaller radius than a wheel, making it progressively less effective as the tire diameter increase
for a given wheel diameter.
5.
Match mounting tires on wheels is also a process where a tire’s installed position on the wheel is specifically selected to
help minimize the final combination’s force variation and/or imbalance.
6.
Tires used off-road are notoriously hard to balance and keep balanced. They are big, they have large tread blocks (subject
to “chunking”).
7.
“Lug-centric” wheels are notoriously hard to balance on common “hub-centric” balancers and are found with many different
rim manufacturers. Toyota also locates the wheel on the hub, via the rim studs. (i.e. lug-centric) and a special lug centric adaptor
should be used to properly balance the wheel.
8.
According to Tru-Balance, wheel-centering products bypass the hub pilot and actually center the wheel to the wheel studs
using the 12, 4, and 8 o’clock positions, resulting in less weight value change during reposition of wheel to hub mounting on wheel
balancing machines.
9.
The way that a wheel is mounted on a balancer will not only affect the accuracy of the balance job itself but also the
repeatability of the balancing results.
10.
You can select different methods of wheel mounting according to practice to have wheel spin straight as possible.
POSITIVE positioning is featured with simple quick operation with suitable cone and nut on the outside of rim, commonly used
with steel rims and aluminum alloy rims with small deformation.
NEGATIVE positioning is used when deformation is noticed with the spin of the wheel. Adopt this method of positioning to
guarantee the accurate positioning of the rim inner hole and main shaft. Especially the thick ALU. Negative positioning is with
the suitable cone on the inside of the rim and the bowl and nut on the outside.
