The cost of commercial tires continues to climb. Natural rubber shortages due to droughts and floods and gouging (at least according to some) keep tire prices well elevated – and they continue to climb. 
A high percentage of NR is used in truck tires because of its low heat buildup compared to synthetic rubber. High prices of all the oil-based raw materials also are going up as the price of oil climbs well-over $110 per barrel.
Because of these financial facts, one of the most appreciated value-added services a commercial tire dealer can provide to a trucking fleet is a scrap tire analysis. There is an incredible amount of information that can be determined from a scrap tire pile in helping a fleet make decisions about its tire program.
If a fleet had the perfect tire program and you were to analyze its scrap tire pile, every tire would be worn smooth and evenly down to the legal limit of 2/32nds for drive/trailer tires and 4/32nds for steer tires.
Of course, this never happens in the real world. If the fleet specification is to retread tire casings one time, then every tire in the pile should not only be worn out, but also have at least one retread…there should be no virgin casings.
Going through the scrap tire pile will probably show:
• Run flat tires
• Sidewall damage (cuts/snags)
• Road hazard damage
• Uneven and premature wear
• Alignment wear
What to Examine
Good scrap tire analysis must identify why a tire was removed from service. So what are the important parameters to record in the tire analysis?
After identifying why the tire is in the scrap tire pile to begin with, you need to record the tread depth. Just recording one spot in the tire is not good enough. You should pick a representative spot on the tire and record the tread depth in each of the major grooves.
This is important because if, for example, the tread depths across the tread grooves were 5/32nds, 4/32nds, 3/32nds and then 2/32nds, it would tell you that there was a vehicle alignment issue, most likely toe-in.
In some cases, you may even want to measure the tread depth 180 degrees from the initial reading. If the tire was removed from service because of severe vibration, it is possible that the tire had excessive radial runout. The only way to identify this condition would be to show that there was a discrepancy in tread depth from one area of the tire to another.
In addition to recording tire removal reason and tread depth, the following information also should be noted:
• Tire make/model
• Tire size
• Original DOT number
• Retread DOT number
• Treadwear condition
• Number of casing repairs
Anybody can record information, but the key is the ability to analyze the data. You are not obligated to purchase a high-priced software package. Using any spreadsheet program that comes with your computer should do the job just fine.
After you have recorded all the appropriate scrap tire pile data into the spreadsheet, the fun part begins. Think of the analysis as playing the “10 questions game.” One question/answer will generate a follow-up question/answer and ultimately bring you to some conclusions that can assist you in making the best decisions about a particular fleet’s tire program.
Let’s go through a typical analysis. How many tires in the scrap pile are virgin casings vs. retreads? If the fleet retread spec is for two caps, the goal is that all the tires are retreads. Age of the tire casing can be determined from the DOT week and year of production. Most fleets have a maximum tire casing age specification.
Excellent information can be gathered from the tread depth data. If the average removal tread depth of the tires with two retreads is on the high side (significantly greater than 2/32nds), that is an indication the tires probably reached their useful life after one retread and you should probably reconsider whether or not to retread a second time.
Also keep in mind that fleets may have their tires retreaded by more than one vendor. The retread DOT number will help identify if there are more tire issues when tires are retreaded at one plant vs. another.
Why tires are being removed from service is another question that must be analyzed. It is possible the analysis shows that most of the right side trailer tires are removed because of sidewall damage. This is a driver training issue and needs to be addressed by the fleet. By recording the number/kind of tire repairs, you may see that some tires are failing early because of an improper repair procedure.
If tires were run with little or no air for an extended period of time, the result could be a circumferential sidewall rupture – the dangerous zipper break. Analysis is critical to give an accurate assessment of what is running well and what is causing early removal issues. Many fleets run more than one model of tire. A serious analysis of the data should look for performance trends between various tire makes/models.
It also is good to link in vehicle information to the tire results. An example would be that a steer tire produced by tire company ABC may have excellent, even wear and high removal miles for a specific tractor. However, maybe the same tire on a different tractor configuration has irregular wear and low removal miles.
Not every tire works well under every vehicle type scenario. Your data analysis should be able to identify the best combination of tire brands for a specific vehicle make/model. This is exactly the type of information the fleet is looking for so it can make the best possible decisions about optimizing its tire program.
Sample size also is an important consideration. You certainly do not want to make conclusions about tire performance and removal reasons with a small tire sample size. Work with your fleets to establish an optimum sample size based on the number of tires running in their operations.
Another important variable to consider is the time of year. Hot summer season is typically when the scrap tire pile may be the biggest. Analyzing scrap piles on a quarterly basis will take into account the seasonal effect on tires.
The last step is for the fleet to implement action items based on your scrap tire analysis. Over time, the scrap pile should see more and more tires that have been retreaded multiple times and removed because they were worn out. Removal because of being worn out will tell the fleet that its tire program is doing very well.
Fleets make decisions based on facts. A commercial tire dealer who can do a successful scrap tire analysis, including a detailed data analysis, will be providing a valuable service to fleet customers.
Do your fleets have serious tire programs, or do they have a lot of work to keep tire costs from hitting new highs? Based on each fleet’s answer to this question, it may be time to get to work on that first tire scrap tire pile and establish the fleet’s baseline.
