Hunter Engineering Co. claims its new ``SmartWeight'' wheel balancing technology, which evaluates static and couple forces independently, can reduce the amount of wheel weights needed by 20 to 35 percent while also cutting the amount of time needed to balance wheels.
The patented SmartWeight system, unveiled at the recent Specialty Equipment Market Association (SEMA) Show in Las Vegas, computes the amount of correction weight by measuring and evaluating independently the ``absolute'' or pure static (shake) and couple (shimmy) forces that cause vibration.
The system then determines each imbalance tolerance separately, the company said, based on the amount of force needed to induce a noticeable vibration on a given wheel assembly. SmartWeight balancing focuses on the appropriate force, according to Hunter, and calls for correction weights only when a force exceeds the limit that will cause a noticeable vibration.
The system also adjusts the tolerances automatically according to wheel size to correct imbalance more accurately.
Traditional balancers use a fixed tolerance on correction weights regardless of the weight location chosen, Hunter said, placing equal emphasis on static and couple imbalance.
However, vehicles are inherently more sensitive to static vibration force than couple force. Testing and specifications by original equipment makers show that wheels can tolerate up to five times as much couple imbalance as static imbalance before a noticeable vibration occurs in the vehicle, Hunter said.
Up to now, the firm said, traditional balancing methods have applied the tolerance to which the wheel is balanced to the displayed correction weight instead of the actual vibration force and applied the same tolerance to both static and couple imbalance conditions.
For most wheel assemblies, Hunter said, this tolerance is too loose for static imbalance and too tight for couple imbalance, resulting in the application of unnecessarily high amounts of correction weight and time wasted on repeated check spins.
Compounding the problem is the fact that most balancers calculate correction weight using technology developed during the 1970s when wheels with rim flanges were common. When applied to current generation alloy wheels, traditional balancing methods require more weight to achieve the same amount of imbalance correction, Hunter said.
In addition, when weights are moved from the rim to the inside of the wheel-as is the case with most flangeless rims-weight placement is narrowed, tape weights are required and more correction weight will be necessary to correct the same imbalance.
Hunter claims the SmartWeight technology can reduce an average shop's wheel weight costs by 25 percent or more while increasing productivity from the tire balancing stations because the tire technicians can use single-spin balances more often.
Hunter has created a separate Web site-www.weightsaver.com-for its new product line/technology.