What's the skinny on cracked sidewalls?

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w30bob
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What's the skinny on cracked sidewalls?

Post by w30bob »

Howdy Boys,

Ok, common sense tells ya not to drive on cracked tires...........but most of us have at one time or another. I'm trying to separate fact from fiction here. Has anyone ever had a blowout due to a cracked sidewall on an NDT? As a kid I used to love old hard cracked tires........they did the best burnouts! I know..........we're not supposed to use tires with cracks in them, but we're not supposed to pull girl's ponytails or stay out until the sun comes up.....but let's get real. :mrgreen:

So I'm walking around Aberdeen on Friday, in the rain, soaking wet and tired from walking the half a football field distance between the few vendors that were still selling stuff..........and in the far corner of the parking lot I see some folks in a covered shelter. So I head over to see if there's any M37 parts I missed and leaning on one of the corner tent posts is a new 9.00x16 NDT with a sign on it that says "$125 each or 3 for $300". I really wasn't looking to buy tires, but I made the mistake of leaning over the tire and touching it. Before I could even look up the owner scooted right over to me and told me he wasn't taking them back home.......so name my price. I was going to say $200 for all 3 when he shouted.....$175 for all 3! I probably could have gotten them all for a hundred bucks, but I started feeling guilty. These had never been mounted and each had a new flap rolled up in it. So I said ok, but it would take me a bit to go get my truck and come pick them up. You know the rest of the story.........I found room in my truck and became the proud owner of 3 orphan NDTs. The next day I took a good look at them and 2 of them are perfect. But the 3rd one has some cracking on the sidewall.....hence this post and my question. So what say ye?


thanks,
bob
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Re: What's the skinny on cracked sidewalls?

Post by ashyers »

Bob,
I'll have more info by weeks end, but here's my limited experience. The front pair is an old set of Goodyears, very well used with minimal cracking. The rear pair is a "new" set of Mohawks with heavier cracking on one side of one (sun exposure?) and minimal on the other. We've had all of the tires on/off the wheels multiple times. The cracking seems to be largely cosmetic to me, but, and this is the kicker, the rubber and carcass of the tires is hard as a rock. The tires do not grip well and their spring rate is nearly infinite. After driving a friend's M37 with some new tires I purchased a set. Long and short is the old tires still have a fair bit of tread, but the new stuff seemed worth the $. We're waiting on the return of the newly powder coated wheels now. I'll post feedback once the new sneakers are on the truck. Tomorrow :)???

Andy
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Re: What's the skinny on cracked sidewalls?

Post by Cal_Gary »

I wouldn't run tires that you described for safety reasons; however, some folks also look to purchase those types for originality-I saw a set on a WC 52 last year that had to be the original treads, as worn, cracked, and dry-rotted as they were. Come to think of it, I still have one in the basement in that condition that was on the truck when I bought it, still holding air to this day, but I won't even consider it for a spare, let alone as one in service.
Just my 2 cents,
Gary
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w30bob
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Re: What's the skinny on cracked sidewalls?

Post by w30bob »

Hi Guys,

Another reason I asked the question is that if you look at tire construction......the plies go from bead to bead, meaning on the 8 ply NDTs there's 8 plies in each sidewall. The outside rubber (that's cracked in this case) appears to be purely ornamental from a load bearing point of view. Of course a case can be made that having a cracked surface on the rubber sidewall will allow the elements to reach the plies, thereby degrading them. Andy brings up another good point, which is the hardness of the rubber itself. While I've never seen an NDT that was "soft", I've got some that are hard as bricks. The tires I just bought are newer Denmans, but I'll have to find the production dates on them, as I believe Denman has been out of business for some time now.

regards,
bob
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Re: What's the skinny on cracked sidewalls?

Post by RMS »

new rubber grips better but old wears better :P I have run date stamps of 1943 @ 50mph no problem. if the inner cores are good and there is no defects on the inside, cuts, bumps, separation, bulging. Johnny 5.0 may say something but who has been pulled over in a m37? as long as their not rayon run them....they are only good for 6 to 12,000 miles
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Re: What's the skinny on cracked sidewalls?

Post by just me »

My old ones were 30 years old, hard as the hub's of Hell and cracked and chunking. They still served me 3k miles until I replaced them this year. I wouldn't have run a load in the truck or gone any distance with the old. And I carried some spares. When I dismounted them, they disintegrated. They were done.
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Re: What's the skinny on cracked sidewalls?

Post by Elwood »

I keep a set of old, cracked NDT tires to use around the shop, but not on the street.

As someone who was been a motorcycle rider and professional technician, I've seen the consequences of neglected, worn-out, and over loaded tires. No thanks.
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Re: What's the skinny on cracked sidewalls?

Post by ashyers »

Bob,
Just put the new sneakers on today. I can say that the old NDT's I've been using are better than no tires, but they are junkola compared to new rubber. The new tires are not broken in yet, but they eclipse the old ones in every respect, except maybe patina.

Andy
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