Effects of Mismatching Dual Assembly Tires

You mismatch your socks and silverware but force things together, and they usually work. Unfortunately, this is far from the case when it comes to your fleet’s dual assembly tires. Mismatched tires have a difference in inflation, diameter, or tire ply and can cause:

  • Uneven tread wear
  • Shorter tire lifespan
  • Uneven load distribution
  • Decreased mileage
  • Tire failure

“Any form of mismatched dual tires is one set too many,” says Doug Jones, customer engineering support manager, Michelin Americas Truck Tires. “Left uncorrected, this problem could cost the tires between 5 to 20 percent of their tread life. So if they are $300 tires and you lose 10 percent of the tread wear, you’ve just thrown $30 a tire out the window.”

Inflation and Load Difference

Keeping your tires properly inflated is a good habit to get into, especially if you use dual assembly tires. An underinflated dual tire will shift the load to its partner, accelerating wear and tear. Load difference will eventually cause tire failure, and that’s a risk you can’t afford to take on the road.

Underinflation is one of the most common problems fleets encounter. It can also be one of the costliest problems to disregard. A 10% difference in air pressure can cause an 11% difference in load distribution. Poorly inflated tires can increase your annual operating costs by $600. That’s a steep price to pay for a problem with a simple solution.

Different Diameters Means Damage

A new pair of tires are more reliable because they’re the same brand, size, and tread depth. Problems occur when you’re working with used tires or pairing new and used. You may check used tires for the same inflation and tread depth and think you’re good to go. But you must pay attention to tire diameters.

Larger tires will always take on more load during operation. That means more wear on the larger tires and scrubbing on smaller tires. Tires with a smaller diameter will rotate faster to keep up with their larger counterpart, resulting in dragging several feet per mile.

Just a ½ inch difference in tire diameter is enough to shift an additional 2% load onto the larger tire. Pairing new and worn tires also shifts 55% more load onto your new tire.

Effects of Pairing Radial and Bias Tires

Radial tires are designed with their cord plies angled at 90° to the direction of travel. Bias tires have multiple, overlapping rubber plies that allow the crown and sidewall to function as one. The two types of plies differ in their deflection, or how the tire deforms when it touches the road.

Radial tires deflect more than bias-ply tires. Bias will bear a more significant load if the two are paired on the same axle. The overload will eventually cut into their longevity and overall mileage.

Contact Bauer Built Tire & Service or visit one of our locations to learn more about our commercial retread tires and our fleet maintenance services.

Categories: News, Tire Care Tips