July 2013: Tech Tips

Caution: Non-OEM Tires & Wheels


When a caller says they replaced the shocks or struts but still don’t like the ride, or the handling isn’t what they expected, our tech team always asks two simple questions about often overlooked causes:

One: Did you consider the tires and wheels?

Two: Did you check the ride height?

The most obvious tire condition that affects ride & handling is tire pressure, but we need toconsider a few more possibilities:


 Motorists tend to buy replacement tires based on price and appearance instead of performance. The sidewall rating and profile (side to side movement resistance) as well as the tread and rubber compound (traction, cushion and rolling resistance) all have a huge impact on ride control performance.

Replacement wheels (rims) with a different size and many Custom-Rimcustom wheels also change the performance dynamics. Replacement wheels often flex differently, some have a different centerline and there will certainly be a weight difference. These changes can improve handling performance, but often there’s a trade-off between performance and driving comfort. Either way it’s important to understand that any change from original equipment tires and wheels is going to affect all aspects of ride control, so it’s best to check before you road test.



Ride height is another potential problem-causer. Be sure to look at the travel limiting bumpers inside the strut bellows and on the vehicle’s frame. Marks on them mean there’s a potential problem: Lower than normal ride height may cause shock bottom out & higher ride height causes top out. If the springs or torsion bar adjustments have been modified, then all of the sprung weight control will not match the OE-designed damping characteristics.

KYB Excel-G shocks & struts are calibrated to help restore the original vehicle-designed handling & control performance. This helps guarantee that the replacement performance outcome will always be correct… unless you overlooked those great-looking, but incorrect tires and wheels!