Quote:
Originally Posted by 2bcs1jrt
I was feeling a little safer having moved up to the 14 inch wheels and tires from 13 inch. Now Im not so sure. One thing I heard AFTER I purchased my 14 inch Marathons is that bias ply are better trailer tires than radials because they are stiffer side walls, although it makes for a bumpier ride. The flex of the radial sidewalls makes them more prone to failure.
Has anyone heard this theory?
Cheri (who wants to know why I always hear things after the fact  ) |
As my screenname implies, my business is tires. I have 26 years in the tire business, and know full well how faulty Marathon Radials are. I refuse to sell them. I see more than my share of them because my company also transports waste tires for other companies. We see MANY separated (tire terminology for when the belts become separated from the rubber they are encased in) Marathon Radials. Sometimes separation in tires is caused by damage, but this is not the case I see with the Marathons. A separated tire can cause severe damage, including the worse case scenario of death due to a wreck.
My personal observation has been that when these tires get around 3 years old, to replace them. Mileage/use doesn't matter.
Without boring everyone to sleep, I'm going try to put it in laymen's term about tires, all tires, not just marathons. Tire rubber is not naturally black, but an off white. The tire industry uses carbon black as a preservative for the rubber against ozone, which dries rubber out. When rubber dries out, besides not flexing easily, it will leak air, possibly separate, and other bad things. Carbon Black keeps the rubber from drying out quickly, and also gives it the black color. If anyone has ever noticed, a whitewall (which doesn't have carbon black) on a tire dry cracks before the rest of the tire.
There also is a trade off between carbon black and traction. Tires with less carbon black have better traction than ones with more carbon black. However, the better traction is negated by shorter rubber life out in the ozone, because it has less preservative. This is my opinion on part (but not all) of Marathon's problem. It doesn't have the proper amount of carbon black it needs, and therefore the rubber dries out too quick. The rubber drying, and not easily flexing, is allowing the steel belts encased in the rubber to break free.........thus separate and peel off.
Tire rubber starts drying out, as soon as it is manufactured. The clock starts ticking the day it's made. All tires manufactured for on road use have a Department of Transportation (DOT) code on the sidewall. If you will look at the last four digits after the word DOT (3 if manufactured before 2000) of this code, you can see the week and year manufactured. This code is usually 12 letters/numbers but not always. Ex: if the last four digits say 3603, then this tire was manufactured the 36th week of 2003.
Just because you purchase a new tire, doesn't mean you got a new made tire. This tire could have sat in a warehouse and then in dealers stock for years, before you got it. The whole time, the clock is ticking on the rubber. It's a good idea to see how fresh made the rubber is, everytime you purchase a tire, either for yourself or your trailer.
Another problem that all trailer tires suffer from is lack of use. Since we don't pull our trailers everyday, our rubber doesn't stay flexing, with all the oils in the rubber being constantly circulated with centrifugal force that our everyday vehicles do. Letting a tire sit, is not what it was made for. It helps the rubber to dry.
Proper maintenance of tires is essential for long life and safety, but with some tires, it won't be enough stop the failure of certain ones........which I strongly believe is just about every marathon radial.
Is anyone still awake?
If anyone is interested, I can explain the difference between radial and bias. Steel belted means something else.