Presentation on theme: "1 Wheel Balance Theory Balance - Unbalance What does it mean?"— Presentation transcript:
1 Wheel Balance Theory Balance - Unbalance What does it mean?
2 Balance.... by definition The stability resulting from the equalization of opposing forces. Equal Force
3 Types of imbalance... Static Single Plane Dynamic Two Plane
4 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 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 The answer: yes, BUT... can you Prove it? At 20 mph.25 oz of imbalance generates.86 pounds of force.86 lbs
9 At 70 mph the force is pounds It's still in perfect balance! lbs NOTE: Speed rated Tires Utilize a Nylon Over-lay to prevent tire distortion at high speeds.
10 One common problem: Improper use of equipment Mounting Method Clean Mounting Surface Calibration Careless Weight Placement
11 Consider this oz. Imbalance Most Computer Wheel Balancers Round off to the nearest.25 oz. 1 oz. Balance Weight Is this a Problem?
12 Is this “rounding off..” a Problem? On most cars, this slight imbalance would NOT be felt.
13 BUT, some Customers Complain about a Vibration at one Speed! Why?
14...vibration at one speed! is why a Vibration may occur at one particular Speed!
15 Natural Frequency Mechanical Objects have there own Natural Frequency
16 Tire & Wheel "Natural Frequency" 4 Revolutions = Frequency of 4 CPS/HZ
17 Tire & Wheel Frequency Change with Speed Vehicle Speed Increasing Tire imbalance frequency increasing
18 Suspension Natural Frequency 14 Hz 12 Hz Range from Hz/CPS
19 Beating - & - Phasing Suspension Frequency Tire & Wheel Frequency Sum of the two above
20 The point at which it is felt
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?