1. Wheel Balance Theory
Balance - Unbalance
What does it mean?

2. Balance....by definition Equal Force
The stability resulting from the equalization of opposing forces.
Equal Force

3. Types of imbalance...
Static
Single Plane
Dynamic
Two Plane

4. If rotated it rotates with Equal Force
What is Static Balance?
Static Balance is when the weight of the wheel and tire assembly is distributed equally around the axis of the wheel rotation.
If static Balance exists the wheel will have no tendency to rotate.
If rotated it rotates with Equal Force

5. Heavy Area Rotates to Bottom
How do you Static Balance this Wheel?
Heavy Area Rotates to Bottom
.25 oz Imbalance

6. Is this wheel in static balance?
.25 oz imbalance
.25 oz weight added

7. ...and, if this wheel is in static balance?
If this wheel is in perfect balance at a speed of 40 mph, will it remain in balance at all speeds?

8. At 20 mph .25 oz of imbalance generates .86 pounds of force
The answer: yes, BUT... can you Prove it?
At 20 mph .25 oz of imbalance generates .86 pounds of force
.86 lbs
.86 lbs

9. It's still in perfect balance!
At 70 mph the force is pounds
It's still in perfect balance!
10.53 lbs
NOTE: Speed rated Tires Utilize a Nylon Over-lay to prevent tire distortion at high speeds.
10.53

10. Improper use of equipment
One common problem:
Improper use of equipment
Mounting Method
Clean Mounting Surface
Calibration
Careless Weight Placement

11. Consider this... Is this a Problem?
Most Computer Wheel Balancers Round off to the nearest .25 oz.
1 oz. Balance Weight
1.12 oz. Imbalance
Is this a Problem?

12. On most cars, this slight imbalance would NOT be felt.
Is this “rounding off..” a Problem?
On most cars, this slight imbalance would NOT be felt.

13. Complain about a Vibration at one Speed!
BUT, some Customers......
Complain about a Vibration at one Speed!
Why?

14. is why a Vibration may occur at one particular Speed!
...vibration at one speed!
is why a Vibration may occur at one particular Speed!

15. Mechanical Objects have there own Natural Frequency

16. 4 Revolutions = Frequency of 4 CPS/HZ
Tire & Wheel "Natural Frequency"
4 Revolutions = Frequency of 4 CPS/HZ

17. Tire imbalance frequency increasing Vehicle Speed Increasing
Tire & Wheel Frequency Change with Speed
Tire imbalance frequency increasing
Vehicle Speed Increasing

18. Suspension Natural Frequency
Range from Hz/CPS
14 Hz
12 Hz

19. Beating - & - Phasing Suspension Frequency Tire & Wheel Frequency
Sum of the two above

20. The point at which it is felt...15 10 5

21. ...and, the complaint...
"...but, I balanced the tires in the FINE/NON-ROUND-OFF mode and...
...it still vibrates at 55 M.P.H.

22. What's the Problem? Mounting Error
Are wheels centered by the center hole?
Hub-centric
Are wheels centered by the lug nuts... or...
Lug-centric
Duplicate O.E.M. Mounting

23. ...also, Consider this Are Tires and Wheels Perfectly Round?
Tire High Spot
Wheel High Spot
Would this Mismatch cause a problem?

24. 15 10 5

25. Match Mounting
Mis-Matched Matched

26. Dynamic / 2-Plane

27. Dynamic Imbalance
1 oz. Imbalance

28. During one revolution