For commercial truck fleets, failure to maintain proper tire pressure could lead to various safety risks and violations while vehicles are in service, costing them much more in the long term.

Improper tire inflation is the leading cause of tires not reaching their full life expectancy. Underinflation causes fleets to prematurely pull tires out of service, while overinflated tires are prone to irregular wear and compromised sidewall strength. Problems also arise when tread depths are mismatched and when fleets mistakenly use the wrong tire for the application, which leads to poor performance and potential hazards on the road.

Keeping tires properly inflated, while also maintaining minimum federal tread depth levels – 4/32nds for steer tires, and 2/32nds for drive and trailer tires – will not only help prevent roadside safety events and violations, it will also extend a tire’s life to ensure the casing can be retreaded.

For many fleets, a successful retread program is a way to maximize the bottom line. By properly utilizing a retread program, fleets can offset initial new tire costs and spread that cost out over multiple tread life cycles.

“Retreading is a vital part of any fleet operation,” explained Tom Clauer, senior manager of commercial product planning, Yokohama Tire. “There are a few exceptions where fleets may choose to use virgin tires exclusively. Even in these situations, retread programs are beneficial for fleets because by selling back the casing, they generate money from a retreading dealer. This can easily offset original tire purchase costs.”

Clauer added that premium new tires can be retreaded multiple times, thus expanding the usability of the casing.

Retread eligibility

It is important that fleet maintenance crews know when and if a casing can in fact be retreaded. According to the Tire Retread & Repair Information Bureau (TRIB), no medium truck, heavy radial truck, or bus tire casings should be accepted for retreading with the following “conditions or injuries.”

External

Ply separation beyond repairable limits; tread separations that cannot be removed during buffing; broken, damaged, kinked, or exposed bead wire; excessive oxidation (i.e., weather checking) extending to the body plies or deeper than 2/32” (1.5 mm); tires worn to exposed belt wires on more than 10 percent of the worn tire circumference, unless a protector belt is to be removed or damaged belts are to be replaced; circumferential cracking; tires with rust or corrosion beyond repairable limits; any signs of weakness or non-repairable injury (softness due to contamination from chemical/petroleum products, ripples, bulges, porosity, etc.); crunching or popping sounds when flexed; surface cuts that exceed the size of a repairable injury and penetrate the cord body; radial ply cracking; or improper labeling.

Internal

Injuries to the body plies in the non-repairable bead area; loose cords on the inside ply or evidence of having been run underinflated or overloaded; non-repairable damage to the inner liner or bead area on tires identified as tubeless; open inner liner splices which expose cord; flex breaks, X-breaks, or impact breaks; porous, contaminated from chemical degradation, or loose inner liners; previously installed repairs found to be defective and unrepairable; or suspected of potential zipper damage, which include any signs of weakness or non-repairable injury (e.g., ripples, bulges, porosity, softness, etc.) in the sidewall, particularly the upper sidewall.

“Technicians and drivers need to know and understand that just ‘sticking’ and measuring tread depths is not enough,” Yokohama’s Clauer explained. “They need to do a complete 360-degree visual inspection. There could be irregular wear patterns in which lower tread depths could be found. The lowest tread depth – not the average tread depth – is the measurement that must be used. Road inspections have set measurements and will look for and use the lowest tread depth they can find.”

According to Dustin Lancy, product marketing manager for North America Commercial, Goodyear, most of Goodyear’s larger commercial fleet customers are retreading as an integral part of their overall tire management program.

Goodyear offers a retread management system called GTRACS that helps track the casing life cycle of a tire. It tracks the health of the casing, how many retreads it has had, and allows technicians to add repair notes into the system.

“When that product comes back from the fleet to be retreaded, we can do the proper inspections to make sure that casing is eligible to be retreaded again and to go back into the fleet for use once again after it’s been retreaded,” Lancy explained.

“A casing is like a $100 bill to a fleet if it hasn’t been retreaded,” Lancy added. “You want to take care of that investment because that is what will help a fleet maximize its total cost per mile over time.”

That is exactly what Canada-based Len Dubois Trucking is doing. Derek Quinn, maintenance manager for Len Dubois Trucking, expects to see improvements in the fleet’s kilometers per tread using the Dana Rhombus TireAnalytics system. The fleet implemented Rhombus in February to track tire health on more than 30 trucks and 138 trailers.

Rhombus provides a guided inspection process via a cloud-based system of record that can help fleets maintain proper tire psi, identify issues to help prevent roadside and safety violations, allows technicians to capture, save, and share images of their tires, and tracks information like tread depth and condition to help prevent over-the-road failures.

Although Quinn and the fleet are new to working with the system, in a short period of time Rhombus has helped the fleet identify a couple problem areas that required immediate attention. One was underinflated tires.

“We noticed when we started checking our units that we had an underinflated tire problem, so we quickly corrected that,” Quinn explained. “We had a staff meeting and talked to our technicians to make them aware of what’s going on. We’ve already reduced our underinflated tires by about 20 percent.”

Rhombus also helped the fleet determine that the maintenance department was pulling tires too soon in many cases, as technicians were not aware of proper tread wear patterns.

“We retread quite a bit,” Quinn explained. “That’s probably most of our tires, and it’s mostly on our trailers. We have an agreement with Michelin where they will warranty our casings up to three retreads. We basically have a written guarantee that the fleet can recap a tire up to three times in any configuration.”

When Len Dubois Trucking buys a new truck, for instance, that asset will come with all-new virgin casings that will eventually run their lifecycle and will be cycled through the fleet’s retread plan, Quinn explained. Currently, a new drive tire will get one set of retreads, then it will get retreaded into a trailer tire. Ultimately, after the casing is retreaded multiple times, it will go onto a unit that is being returned to the dealer and cycled out of the company’s system.

Quinn expects that by retreading and using a digital tire management program, the fleet’s tire costs will drop 10 to 15 percent in the first year alone using Rhombus.

When is it best to retread?

When it comes to retreading, also referred to as recapping, there are a lot of factors to consider, noted Shaun Hartoog, digital solutions specialist at Dana. For instance, he explained that there are many data points in terms of the age of the tire casings and the number of repairs those tires have gone through.

“When it comes to forecasting, what we help and show customers is what they are getting for their average miles per 32nds [of an inch] of tread,” Hartoog explained, adding that Rhombus can track tire life cycles by make, model, and size. “We can show them the difference between new tires and recapped tread patterns. We can show customers the difference between performance … and then we can provide them a forecasting based on previous measurements.”

Shane Feasel, senior brand manager for Bandag, Bridgestone Americas, explained that although retreads are a best practice in extending the useful life of a tire for many successful fleet operations, the process must start with a high-quality tire and casing.

“As a means to ensure the longest useful life of the tire casing, proper tire inflation and proactive maintenance is critical, which is a great opportunity to leverage [Bridgestone’s] IntelliTire for TPMS monitoring,” Feasel said. “Once a tire reaches the end of its initial tread life, dealers can utilize a tool called BASys to brand and track the tire casing as it is sent in for retreading.”

Understanding when to retread and monitoring the integrity of casings can also help fleets unlock the full potential of a tire’s performance and profitability, Feasel added.

“Determining when to retread can depend on a fleet’s application, but many will start with new tires in the steer position before retreading the casing and moving it to the drive position, followed by the trailer positions,” he explained. “This helps to maximize the fleet’s investment. In some high-scrub industries, it might be more productive to use retreads on the steer axle from the start.”

When taking proper tread depth readings, Feasel emphasized the importance of utilizing the correct type of gauge and tracking solution.

“Be sure the technician is using a gauge designed for commercial tires and one that is large enough to take accurate measurements,” he pointed out. “To properly assess tread depth, be sure to take three separate tread measurements [left, right, and middle] on each tire to ensure accuracy. An average of the three measurements can be recorded. In most states, 2/32nds remaining tread depth is legal, but many fleets set their own tread depth standards for steer, drive, and trailer positions to preserve casing life for retreading.”

While measuring the remaining tread on any tire, it is important to visually inspect the tire for obvious wear and operational conditions that may be present such as cuts, snags, holes, and debris lodged in the tread.

According to Brandon Gray, operational marketing manager, B2B Services, Michelin North America, a good example of analyzing tire usage data to improve retread performance is via Michelin’s retread analytics tool, SMART (Strategic Michelin Analytical Retread Tool).

SMART analyzes the conditions and causes of why tires are pulled out of service and can recommend changes in maintenance practices and casing asset management specifications. For example, upon completing an analysis of thousands of casings submitted annually for retreading, Gray said that a large national fleet customer noted a particularly high casing rejection rate due to sidewall impacts originating from one of their maintenance locations. Upon further investigation, the fleet’s maintenance vice president discovered that the air pressure recommendation at that location was 10 to 15 psi higher than the company standard.

The higher tire pressure correlates with a higher-than-average casing rejection rate due to sidewall impact damage. According to Gray, that maintenance manager changed the outlier air pressure recommendation to be within the company standard, and this damage condition ended up falling back within the fleet’s norms. That move resulted in several hundred tires being accepted for retreading that would have previously been rejected, Gray noted.

“It’s typically time to retread a tire when the original life tread meets the fleet specifications to pull points,” Goodyear’s Lancy pointed out. “That’s something that is known ahead of time before the tire can be retreaded. But these pull points can also vary by position, so all fleets are required to pull steer tires when they reach 4/32nds remaining of tread depth and drive and trailer tires at 2/32nds.”

In addition to analyzing the exact pull points on when they remove tires, Lancy advised that fleets also do a thorough visual inspection. Goodyear’s TireOptix program can help technicians look not just at the inner and outer sidewall, but also around the whole tread of the tire to make sure there is no damage.

“Damage to the tread – if that perpetuates – that could potentially cause bigger issues down the road if those are not addressed early,” Lancy emphasized. “Number one would be to check tread depths and make sure that you’re meeting the fleet specifications and, minimally, meeting DOT specifications. Then, do a visual check to make sure those tires are removed at the proper time so they don’t cause any roadside service issues down the road.”

When technicians are checking for tread depth, they should also make sure that a tire is wearing evenly, Lancy added. Ensuring even wear across the tread, especially for a steer tire, can help a fleet identify issues where the truck might need to be aligned or tires should be moved into different positions, he explained.

Lancy further emphasized the importance of technicians keeping an eye out for mismatched duals in the drive and trailer positions.

When it comes to implementing a successful retreading program, it is important for fleets to remember that quality new tires could eventually be retreaded multiple times. It is also critical that fleets know the manufacturer they are working with and that they continue tracking tires from the original new tire installation to that casing’s final tread cycle.