When tires are new they seem to be without blemish and they have that innocent and promising appearance. While I don't know what a new pair of shoes means to you, but for me whether the shoes are for my feet, car, or rig, after purchase and mounting I feel like I can go anywhere. Trouble is there are numerous obstacles lying in wait to compromise the integrity of travel.
I suspect that for as long as man has been around he's found ways to cover his feet to travel over-yonder and thereabouts. Today, not many of us would consider going anywhere without shoes. Thus, we determine what kind of shoe we wear depending upon the job or destination.
As time slips quietly by, if we were to examine our shoes we'd discover irregular wear patterns emerging. And, just like with people's shoes there are many varied reasons why tires go bad. Apparently, the physical environment plays a significant role as to how people's shoes and tires behave.
Our bodies are designed for mobility. And, because we are all constructed differently the wear patterns our shoes develop are very similar to the irregularities that tires acquire. Regardless of how efficient the manufacture of the running gear and installation processes may be there are always minute differences between each person or rig. And, as time marches on these irregularities begin to manifest in odd, baffling and downright disturbing wear patterns. An example would be - break a leg or damage the back and your shoes will eventually show the injury. Consequently as tires race down the abrasive highway microscopic particles are removed from the tread, which eventually transform the once magnificent tires into uneven or odd wear patterns.
Although structural imperfections eventually cause tires to have a reduced life expectancy, these are not, in my opinion the main culprits for premature aging or death. Even though I do not claim to be an expert relating to tire problems, over the years I have spent considerable sums of money buying and repairing tires. Therefore, from my perspective the major reason tires expire prematurely is not only due to road hazards and bruising curbs, but primarily due to excessive heat.
Heat build-up is a natural process of friction caused by an abrasive highway. And, adding fuel to a fire the air within the tire casings are expected to carry not only their own weight but the weight of the tractor trailer and what ever the load may be. Likewise, if too much heat develops the friction magnifies and a failure usually develops.
Often, when we have discovered a tire problem and corrective action is initiated unseen damage has unfortunately already occurred. While tires like the human body can take punishment there is always an associated cost. Often this cost does not manifest till some unexpected moment well into the future. And then, when it does become clear that a problem is imminent, we often cannot seem to understand why. We conveniently forget that months or years ago something happened that predicated this imminent situation. Thus, we often resort to blaming something entirely unrelated.
The air inside the tire casing when first inflated never goes bad. However, when the air was installed it is seldom moisture free. This moisture can or does attack the steel rim, which creates microscopic pits. And, if allowed to continue unchecked eventually allows minute amounts of air to escape around the steel bead. Plus, this moisture also seems to cause additional thermal expansion beyond what a moisture free air environment would be like inside the casing.
So, when a tire develops a leak via valve stem, bead, nail hole, etc., and more air added we inadvertently add more moisture, which compounds an already insidious problem. Thus, we have directly; although unwittingly added even more irregular air expansion which creates further wear and tear.
Assuming that a proper Pre-Trip Tire inspection was complete - for some strange reason many of us seem to forget, or maybe never realized that when we have driven for a couple hours at posted highway speeds -- thermal expansion of the trapped air inside tires occurs naturally. Tire manufacturers know about this reality and from what I've read have designed their tires to accommodate this actuality.
Whether or not a tire check was initiated prior to trip departure, but an enroute tire check was conducted with the standard air gauge anyone can be fooled into believing that the inflation pressure is either right or wrong. Therefore if the tires were not allowed to dissipate the heat by cooling down to current and maybe the original ambient temperature any driver may believe that more or less air is needed. Consequently, a big mistake may have occurred by removing or adding air to any tire suspected of being under/over-inflated
There are charts that show how to perform correct air inflation status of enroute tires. But, I've never met anyone, including myself that thoroughly understands these charts. Furthermore, if the standard air gauge is not calibrated against a known correct pressure setting then the so-called trusty gauge may not only be in error, but actually cause the creation of errors. Sadly, the unfortunate result is - all too often under or over inflation is the norm, which translates into excessive heat or wear. Like it or not, if the tires are not pre-checked with an accurate gauge then unwarranted wear will be the result. And, of course if we don't take care of our tires they will let us down when we least expect or can afford it.
This article is not an attempt to dazzle you with brilliance or baffle you with confounding intellectual mumbo-jumbo. Instead, it is meant only to provide practical information that should help any driver better manage the rigorous road challenges faced each and everyday.
The question is - how best to check tires. In my non-expert opinion a pre-trip tire inflation inspection should be initiated with an accurately calibrated air gauge. Of course this assumes that the tires have been sitting for a couple hours from any previous OTR use so as to become the same ambient temperature. If the air gauge has not been recently calibrated for accuracy then I would be forced to conclude that its accuracy is dubious at best and therefore unreliable.
Next, comes the periodic enroute tire inflation checks. As mentioned earlier, I can see no reliable way to accurately use the standard air gauge to efficiently and expeditiously inspect enroute tire inflation status. Therefore, it is my belief that only thumping a tire can offer any degree of practical and time efficient knowledge as to whether or not a tire is of sufficient air pressure to continue driving in as safe a manner as possible or practical.
At the end of the day or the conclusion of a trip when the driver fill's-out the vehicle safety status form I know of no way to accurately use the air gauge due to tires still being warmer than ambient temperature. So, thumping the tires seems to be the best manner of efficiently completing the tire portion of the vehicle status report.
In conclusion, a conscientious driver is left with trying to determine what is the best, most efficient and reliable tool to thump with. Because I have spent considerable amounts of time researching this not-so obvious dilemma I can only refer to Accu-Thump as being "The Correct Way To Thump Truck Tires". I make this statement not because I make and sell them; but because I know of no other hand tool that can or will provide the same amount of reliable data regarding air inflation status of any truck tire.
For those who don't or won't take the time to sift through my web pages - here's a few essentials as to what a tire thumper ought to embody.
There are several other common sense requirements for a tire thumper. But, if a tire thumper does not have these 4 essential features then I would reconsider the merits of the tool. After all the purpose of a thumper is to provide the driver with as much information in the shortest possible time so the driver can get on with the business of driving.
I am collecting as much information relating to RoadGators as possible. And, I sure would appreciate any information you may care to share on this sensitive, but seldom discussed subject.
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Created: 05/15/2000
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