Wheel Balance Theory Balance - Unbalance What does it mean?

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

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

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

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

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

...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?

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

It's still in perfect balance! At 70 mph the force is 10.53 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

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

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?

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.

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

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

Mechanical Objects have there own Natural Frequency

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

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

Suspension Natural Frequency Range from 10 - 15 Hz/CPS 14 Hz 12 Hz

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

The point at which it is felt... 15 10 5 0 10 20 30 40 50 60

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

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

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

15 10 5 0 10 20 30 40 50 60

Match Mounting Mis-Matched Matched

Dynamic / 2-Plane

Dynamic Imbalance 1 oz. Imbalance

During one revolution