Wheel Balance is Only Part of the Solution

Hunter Road Force video - see it in action

What you need to know about wheel balance
What causes excess wheel vibration

The Hunter GSP9700 Road Force balancer

Beyond the traditional functions of a wheel balancer

Measuring tire/wheel uniformity
Measuring rim runout and force matching
StraightTrak® lateral force measurement

Wheel Balance is Only Part of the Solution...

What you need to know about Wheel Balance & Wheel Vibration Control

At 60 miles per hour, an average size tire rotates 850 times per minute. At this speed, slight variations in balance, sidewall stiffness or roundness can cause the wheel to literally slam into the pavement 14 times a second. The ultra-sensitive road feel of today's vehicles gives drivers a hands-on detection of vibration, a warning of potential problems. Unchecked, excessive wheel vibration can result in expensive damages and unsafe driving conditions such as:


			Excessive Tire Wear Damage to Suspension and Steering Components Unsafe Steering and Handling

What Causes Excessive Wheel Vibration?

Wheels Out of Balance

Static wheel balance measures only "up and down."

Static wheel balancing uses a single weight plane and only addresses "up-and-down" imbalance. This is simply not adequate for today's wheel vibration sensitive vehicles.

Dynamic wheel balancing uses two weight planes. This eliminates "up-and-down" and "side-to-side" imbalance. Dynamic, two plane wheel balance should always be requested, even on custom wheels when hidden weights are required.

Dynamic wheel balance also measures from "side to side."

Wheel Force Variation

An out of round tire (runout) causes wheel vibration.

A stiff spot hitting the pavement causes vibration.

A perfectly balanced tire can still vibrate due to Force Variation.

Wheel Force Variation is most frequently due to wheel runout or uneven tread or sidewall stiffness in the tire. Runout is when a tire or rim is out of round when rolling; frequent causes are a bent rim or uneven tire wear.

Uneven tread or sidewall stiffness can be found in new or worn tires. Tires by design are never uniformly flexible throughout nor are they perfectly round. And no two tires are exactly alike in these characteristics.

How Wheel Force Variation is Corrected

OEM Match Mounting matches a high point or stiff spot on a tire...

with the low spot on the rim, for maximum roundness.

1. Match mounting a tire and rim by matching the high point or stiff spot in the tire with the lowest spot in the rim, can make the wheel "round when rolling."

2. In some cases a wheel is so out of round it should be replaced.

3. In some cases a tire with excessive Force Variation is defective.


Tire Pressure and Wheel Alignment

Improper tire pressure and/or misalignment causes irregular tire wear which creates and amplifies imbalance, resulting in wheel vibration. Alignment can be adjusted and wheels serviced to reduce or stop the vibration. Ask your technician.

Steering and Suspension Components

Steering and suspension components need periodic inspection. They can eventually wear out resulting in wheel vibration. Excessive wheel vibration from other causes can also shorten steering and suspension component life.

Other Hidden Causes of Wheel Vibration

Wheel to axle mounting error Brake component wear or failure Drive train or engine component wear or failure Vehicle component characteristics A knowledgeable technician with proper training and equipment can diagnose these problems. But, the only way to rule out all wheel-related vibration is with the Hunter GSP9700 Vibration Control System.

	GSP9700 Road Force Balancer
	Solves Wheel Vibration and Tire Pull Problems Balancers and Aligners Can’t Fix
			Going far beyond the traditional functions of a wheel balancer… The GSP9700 measures radial and lateral tire forces and provides instructions for solving ride and handling problems such as tire pull and wheel vibration that balancers and wheel aligners cannot fix. Hunter’s GSP9700 is endorsed and recommended by vehicle manufacturers and proven by repair facilities worldwide as the industry standard in... Wheel Balancing Tire Road Force and Rim Eccentricity Measurement Tire Pull Lateral Force Measurement
	Benefits of the GSP9700’s “Three-In-One” Diagnostic Repair Capability:
	Solves Wheel Vibration Problems Balancers Can’t Fix Detects non-balance, radial-force-related problems associated with: Tire uniformity. Tire and rim runout. Wheel-to-balancer mounting error. Improper bead seating of tire to rim. Faster Troubleshooting & Repair Quickly calculates the contributions of the rim and tire to radial vibration problems and presents the technician with step-by-step repair instructions. Identifies Potential Vehicle Pull or Drift Problems The StraightTrak® feature measures lateral tire force, then applies that information to the set of tires, providing multiple placement choices to eliminate or minimize tire pull problems – an otherwise unfixable vehicle complaint during alignment service. Dramatically Improves Ride Quality & Customer Satisfaction Duplicates wheel vibration measurement and tire/wheel matching methods previously used only by vehicle manufacturers to provide that “new car ride.”		Hunter’s exclusive Road Force Measurement® System simulates a road test to identify radial force vibration and tire pull* problems.

Measure Tire/Wheel Uniformity

Road Force® Measurement

The exclusive Road Force Measurement® system applies up to 1,400 pounds (635 kg) against the tire. The loaded roller detects non-balance, radial-force-related vibrations caused by eccentricity and constructional variation of the tire and wheel. Unlike non-contact measurement, the roller samples the entire footprint of the tire including the sidewall’s contribution to ride quality.

Lack of tire uniformity is a common and often hidden source of vibration. As a tire rolls, it flexes as if it were made of springs. Vibration results when tire stiffness is not uniform.
Lack of tire uniformity is a common and often hidden source of vibration. As a tire rolls, it flexes as if it were made of springs. Vibration results when tire stiffness is not uniform.

Non-contact runout measurement systems often provide inconsistent results and do not take into consideration the contribution of tire sidewalls to vibration problems.

Measure Rim Runout and Force Matching

	Rim runout can be measured without removing the tire... The GSP9700 measures lateral and radial rim runout without removing the tire from the rim and quickly indicates if runout is tire-related. Runout can also be measured at the actual bead seat on a bare rim.	... or directly at the bead seat on a bare rim. The GSP9700 slowly rotates the wheel automatically during measurement.* The GSP9700 then calculates the contributions of the tire and the rim to the vibration problem and presents the technician with repair instructions.
	Hunter’s patented ForceMatch® feature cancels the stiffest point of tire radial force variation with the low spot on the rim. This helps eliminate vibration by minimizing the effects of radial force variation and rim runout.	Offering the same service as vehicle manufacturers, the GSP9700 matches the stiffest area or high spot on the tire with the lowest spot on the rim to cancel vibration caused by radial force variation and provide the smoothest possible ride.

StraightTrak® Lateral Force Measurement

Solve Tire Pull Problems With the Hunter GSP9700 That Alignment Service Can’t Fix
	Tire-related pulls are caused by lateral forces in the tires. Lateral force is the amount of left or right pull force created as the tire rolls along the road. This condition may cause a vehicle to steer away from straight-ahead. These forces are primarily created by conicity and cannot be detected during standard balancing or alignment service. Deliver the Ultimate in Customer Satisfaction The StraightTrak® LFM feature measures lateral tire force during the GSP9700’s Road Force Measurement® test. The GSP9700 then applies this lateral force information to the set of tires, providing the technician with optimal placement choices about the vehicle.

We make no guarantees or warranties, either expressed or implied, with respect to the data on this site. All dollar amounts, rates, specifications, equipment and other data are subject to change without notice.

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