Why the GSP9700?
Eliminate Tire and Wheel Vibration with the GSP9700 Road Force Measurement®
Hunter's GSP9700 is both a balancer and a vibration control system. It is also a Road Force Measurement analyzer for passenger car and light truck tire/wheel assemblies.
Each tire/wheel assembly is tested for the amount of dynamic/static imbalance and Road Force.
The GSP9700 simulates a “road test”, with a unique “load roller” which applies up to 1400 lbs of force against the rotating assembly. The roller measures the loaded runout of the assembly (deflection while under load) and automatically recommends corrections when needed. The GSP9700's technology eliminates many of the time consuming, subjective and often non-productive manual measurements previously used to diagnose and repair ride disturbance concerns.
The following image shows an example of a GSP9700 diagnostic screen.
While driving a vehicle, consider all the wheel-related items that can cause vibration
Up until now the wheel service industry could just balance wheels. The GSP9700 fills the gap doing 75% more than wheel balancing.
Let's review some of these issues:
Have you ever heard a customer say he is still receiving wheel vibration complaints after he has balanced wheels? Many people do not realize that balancing is only a small portion of wheel vibration. If the wheel never came in contact with the road, then balancing would be sufficient. A square wheel can be balanced, but a square wheel will not give a smooth ride.
Not usually checked until there is a problem. Bent rims or defective tires might be found “by an experienced eye,” but we all know that most operators of this type of equipment have little experience or training. Is it the runout in the rim, tire or a combination? How much is too much? Is it affecting the ride quality? These questions are tough to answer. Runout is usually considered after the customer comes back complaining. This diagnostic time is usually done at the expense of shop labor profits and can be time consuming. What about the customers who have a problem and don't return going to another shop looking for an answer?
Many rim manufacturers measure runout during the assembly of the rim. The valve stem location is sometimes drilled to the request of the OEM at the low or high side of runout or a paint dot or stamp is placed at the identified location.
Many rims on the market today are also purposely designed so that the pilot hole is .002-.004" off-center to allow for adjustment capabilities by the assembly lines when encountering force variation on the tire. It gives the chance to adjust for tire force variation if runout is induced into the rim. But up to this point ONLY BY THE OEM!
Up until now, anyone could measure rim runout at the bead seats with a dial indicator. The drawbacks? It's too time consuming. The GSP9700 will automatically measure the inner and outer bead seat and determine the effects on ride quality.
Force Variation (Tire Uniformity)
Radial force variation is the amount of change in stiffness of the sidewall and footprint when a load is placed against the tire. There are specifications and acceptable limits from tire manufacturers. Up until now, force variation has been measured only by OEM's in an industrial setting using equipment in the range of half a million dollars. For example, a tire and rim could be perfectly round when measured with a dial indicator (free runout) and the wheel will still vibrate when driven due to excessive force variation. Many tires on the market today have a “paint dot” or mark on the tire that indicates either the high side or low side of force variation. Many have attempted to solve vibration problems by blindly “Lining up the dot” with the valve stem. The operator assumes the “dot” is the high point of radial force of the tire and the wheel valve stem hole is the low point of runout of the rim. Unfortunately, this is not always true. Many tires are not marked and many wheel manufacturers do not use the valve stem as the low point. Other OEM's use the marks to indicate high points instead of low points! The GSP9700 eliminates any guesswork. The locations of runout and tire force are quickly located and measured. The GSP9700 also automatically determines if they can be used to solve an existing non-balance related vibration, before any extra work is performed.
The wheel, when balanced, must be mounted on the vehicle the same way it came off the balancer. All too often, the technician improperly mounts the wheel on the vehicle off center and the balance is compromised.
Today's vehicle designs are lighter and more sensitive to road feel. It has become more critical to be aware of wheel mounting on vehicles to eliminate vibration during balancing.
The GSP9700 will automatically alert the technician when a mounting error is detected on the balancer, thus preventing improper centering on the balancer from taking place.
Hunter Engineering chose a better direction.
How to eliminate tire and wheel vibration with the GSP9700