Bias ply tires vs steel belted radials after 6 yrs

[L78CHEVELLE]

I have a question to ask about steel belted radial tires compared to rayon nylon bias ply tires. I have a rollback I use as needed and have had some type of rollback for 40 years. I install the best radial tire Michelin sells on these trucks. I drive them about 5 thousand miles a year at most. Every 6 years I have to replace the radial tires no matter how good the tread because the steel belts in them rust and the side ways are in danger of blowing out. I have had side walls blow out at least three times in the last 25 years on tires that are 6 to 8 years old. On the other hand I have bias ply tires with new tubes that are 74 years old and show no problems. The truck tires I have take 60 to 80 lbs of pressure while the bias ply tires with tubes take 32 pounds. If you put steel belted radial tires on your flathead and drive it a few hundred miles a year are the steel belts safe beyond 6 or 7 years? Any one that drives their car daily and put normal miles on it have experience with steel belted radial tires 6 years are older?

[1931 flamingo]

What size tires/wheels on the rollback?? Is this like an F-450 or 550?? Or a "full size" r/back??
Paul in CT

[bobH]

I don't know the 'real' and 'technical' answer, but can offer the following...
Tire guys (dealers) around my area generally agree that 7 years is about max for radials.
Additiionally, there is a street rod club in my area that does a safety check for cars within their club, and outsiders too, and they fail any car with radials over 7 years.
My personal experience... I've had a blowout on one radial that was over 7 years. It had tread that was 'near-new'. I don't know if this is related, or significant.
My bias tire experience is very limited. I've got one car that had 60+ year-old tires on it when I got it. I drove it for awhile, that way. No problems. I eventually bought new bias tires for it, and I figure these tires are the last that I will have, for the rest of my years.
All of which reminds me... My modern (44 yr-old) pickup has radials which are well over 7 years. One of them has a 'bubble' and makes bad noises when in motion. I think it is near the end - sounds like, and looks like it will blow sometime soon. These tires still have at least half tread.

I found an article on life expectancy due to aging, on the Tire Rack site. Several opinions there, mainly based on country, but the general idea can range from 5 to 10 years, with 10 years being the max. Several comments on 6 years max.

[BlueSunoco]

But, if you keep tires out of the sunlight they will last a little longer, right? Cars that are always garaged don't have the same problem.

And, you guys that live in Arizona, So. Cal., Texas, Florida suffer from this a lot more than guys that live up north. The sun destroys everything on a car that is petro based,,,weatherstripping, interior trim, etc.

[expavr]

My personal experience with radials and sidewall failures relates to their use on a 1993 Chev P30 RV chassis. I think that the sidewalls on a radial regardless of brand flex more and are way less tolerant of heat build up. If I didn't carefully monitor the air pressure too high or low, heat became a problem and sidewall failure would occur. I had the best luck avoiding sidewall failure by holding the air pressure 5-10# below the recommended max. I put Michelin truck radials on my 40 Tonner which are a significant improvement over the bias ply Firestone tires when it comes to steering control at high speeds (50+ MPH). The downside is that the ride is a lot stiffer with the wider radials which are inflated much higher than the bias ply tires.

[L78CHEVELLE]

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Originally Posted by BlueSunoco

But, if you keep tires out of the sunlight they will last a little longer, right? Cars that are always garaged don't have the same problem.

And, you guys that live in Arizona, So. Cal., Texas, Florida suffer from this a lot more than guys that live up north. The sun destroys everything on a car that is petro based,,,weatherstripping, interior trim, etc.

The point I'm asking about is not the sun dry rot, or the number of miles, or what part of the country the tires are used in, but my experience is if you have a steel belted radial tire that has never been on the road after about 6 years the steel belts are weak from rust because of their age. Never had a flat on any of my trucks with tires 5 years or newer. My local tire dealer will even give me a trade in on tires that are less than 5 years old when I match up tires on something I buy. My dealer has also sold me tires at big discounts that have been in stock over one year. I wonder if the steel belted radials on flathead Fords are safe after 6 years no matter how they are used compared to bias ply tires without steel belts? Something to think about before you buy radials or if you are driving your valued Ford on steel belted radial tires that are over 6 years old.

[deuce_roadster]

My understanding is that the rubber compounds used in todays tires is very different from the old time ones and is way more susceptible to the ozone that is in the air and it breaks down the new rubber. Look up ozonolysis and what it does.
I just noticed that the tires on my car trailer are developing small cracks in the bottom of the tread. Time to change them.

[VeryTangled]

IMHO, at 6+ years you should buy new ones, radial or bias. Just a cost of doing business in this neighborhood. Sorry to say. A little money now, versus a lot of money later.

-VT/JeffH