Widebase tires continue to grow in popularity. In fact, there has been exponential growth with sales doubling every year since widebase tires were first introduced more than 10 years ago.

The concept of widebase is very simple: one tire replaces two tires. However, a widebase tire is not double the tread width of two dual tires. The most common widebase is a 445/50R22.5, with about 70% market share. The nominal tread width of 445 mm is about 17.5 in. when you do the math conversion. The 11R22.5 dual size tire has a tread width of 11 in. Two dual 11R22.5s equate to 22 in. of tread. Therefore, one widebase is only about 80% the tread width of two duals, which simply means that the tire is working a little bit harder during every revolution. Maintaining proper tire pressure is the key to success with widebase tires to keep them running cool with the proper tire footprint.

So what do fleets find so rewarding when spec’ing their drive, trailer and dollies with these tires? Fuel economy, weight savings and reducing both tire and wheel inventory are the three big reasons why fleets are impressed with these new generation widebase tires. More and more tire manufacturers are offering a complete lineup of tread designs. In addition, a hidden benefit is drivers report they just like the way the tires feel going down the highway. Since they are wider than the duals, road rutting does not affect widebase tires.

If a fleet currently is spec’ing dual tires with steel wheels and now decides to spec widebase in combination with aluminum wheels, there is up to a 1,000-lb. weight savings. This will allow for increased payload and lowers the return on investment.

Other side benefits include improved brake cooling; also, mechanics will no longer be concerned with matching dual tires to the proper tread depth and circumference.

A benefit of spec’ing widebase tires on a trailer dolly is that one man can now easily pick up and move a dolly all by himself. It is almost impossible to manually move a dolly equipped with duals.

Load requirements are key when choosing what size widebase tire to spec. The 445/50R22.5 has a rating of 10,200 lbs. at 120 PSI. The other option is to use the 455/55R22.5, which can support about 8% more load at 11,000 lbs.

But there are considerations when spec’ing widebase tires. It is quite common for dual tires to survive two retread cycles. But widebase tires are heavier, generate a lot of heat and are working a little harder during every revolution. That translates into a one retread expectation for widebase tires—if air pressure is properly maintained and the tire is not abused—or if the truck is not run overloaded or driven above the speed limit.

Handling a widebase tire and wheel assembly is more difficult than duals because the combined weight is approximately 220 lbs. with a widebase tire mounted on an aluminum wheel.

It also is important to be cognizant of the effect the axle may have on widebase tires. Replacement of standard dual wheels with single tire/wheel assemblies on existing drive, trailer and dolly applications may adversely affect the loading on the axle and/or wheel-end components. This can alter the stresses in the bearings, spindle, hub and axle housing. The load carrying capability could be reduced and shorten the anticipated service life of these components.

There are three different wheel outsets available with a 14-in. widebase wheel: 0, 1.3 and 2.0 in. As outset increases, higher loads are placed on the outer bearing, which can reduce bearing life, cup rotation and promote wearing of the spindle.

If fleets are spec’ing widebase tires on their new equipment, it is recommended to spec the wider axles with 0 wheel outsets. For retrofitting existing axles with duals to the new widebase, the 2-in. wheel outsets currently is the most common scenario.

Widebase tires are here to stay and will continue to grow over the coming years.