Rubber hardness??? (1 Viewer)

[ashooter]

Okay smart-asses, please limit the "rubber hardness" comments... I'm asking a serious question here... No really, I AM! Seriously.

I asked this question in another thread, but got no answers. I figured a lot of people might benefit from whatever insight comes about here, so I'm giving it a whole new thread....


Puncture resistance vs. chipping/breaking:

I have searched, but all I get is "Toyos are made from harder rubber" or "Maxxis are made from softer rubber"... My concern is, if the Toyo MT's are made from a "harder rubber" so they're more puncture resistant and last longer, are they automatically more prone to chipping and having chunks break off the tire when driven on rough limestone?

For example, I get the impression that the Cooper S/T-C is made from a softer rubber than the S/T (not STT) because the S/T was having chunks break off in some types of rock.

* Am I stuck having to choose between puncture resistance and having tires that won't chip/break on rough rock? Or are these two qualities not mutually exclusive?

Any way to know the answer to that other than just buying 'em and trying 'em?

 

[MoJ]

There's always a tradeoff.

To complicate things further, consider that many of the comments regarding tires, hardness, wear, puncture resistance, etc are less than accurate and often based on someone's experience with one set of tires or what they heard on some internet forum.

My point is it's nearly impossible to make the tire decision process an exact science.

 

[Spud]

Durometer is one of several ways to indicate the hardness of a material, defined as the material's resistance to permanent indentation. It is named for instrument maker Albert F. Shore, who developed a measurement device called a durometer in the 1920s. The term durometer is often used to refer to the measurement, as well as the instrument itself. Durometer is typically used as a measure of hardness in polymers, elastomers and rubbers.[1]

 

[ashooter]

Durometer is one of several ways to indicate the hardness of a material, defined as the material's resistance to permanent indentation. It is named for instrument maker Albert F. Shore, who developed a measurement device called a durometer in the 1920s. The term durometer is often used to refer to the measurement, as well as the instrument itself. Durometer is typically used as a measure of hardness in polymers, elastomers and rubbers.[1]

So how do I figure out the "durometer" measurement of different tires before choosing which one to buy?

 

[Spud]

So how do I figure out the "durometer" measurement of different tires before choosing which one to buy?

Softer vs. harder is not the only determining factor. Soft tires get better traction but wear faster. Harder tires wear better but not as good traction.

Best bet is to go on recommendations from other mudders that are driving in same/similar conditions as you plan to be on. Ask a question about what tires would be good for your application and surface.

 

[ashooter]

Best bet is to go on recommendations from other mudders that are driving in same/similar conditions as you plan to be on. Ask a question about what tires would be good for your application and surface.

That was what "the other thread" was about - https://forum.ih8mud.com/80-series-tech/204577-most-puncture-resistant-tire.html

My paradox is that the off-pavement driving I'll be doing is mixed between broken up limestone and greasewood etc. The limestone is HARD stuff with a lot of gypsum, so I'm a little worried about tread blocks breaking/tearing off if the tire is too hard. The greasewood gets broken off by the front tire, which leaves a little stob sticking up that thinks it's a nail... so if the tire's too soft, it's going to get punctured really easily. I can't count the number of flats I've had with various brands of AT type tires over the years - Cooper, General, Yokohama, Bridgestone etc...

Kind of a catch-22, but I had at least one guy from Arizona say that the Toyo MT is pretty much good to go as far as the greasewood... So I would hope it will hold up reasonably well on the rough rock, as long as I go slow.

 

[ashooter]

... or maybe I'd be better off with a softer tire, a plug kit, and a good compressor.

 

[scottm]

I think it's the belting that's going to resist punctures. Somewhat harder or softer rubber probably won't make much difference to a nail or sharp stick. So I think you're talking about two unrelated attributes, not a trade-off. I had one sidewall tear in my years of working construction, when I drove through a bunch of scrap lumber under the snow. I drove over nails every day, somehow didn't get a flat from them. I don't think any tire would've resisted that sidwall tear.

 

[-Spike-]

I think it's the belting that's going to resist punctures.

What he said.

-Spike

 

[Nay]

I think you are over analyzing the science. I think you would do very well with any of the "modern" MT's:

- Toyo
- MTR
- Trxus
- Cooper

There are others. I've had my sidewalls at under 15 PSI compressed and pinched up against a rock while pivoting without any damage, and this is a soft compound.

Of course, sharp limestone and pointy sticks are a different story, but your best bet is to look at the amount of side lug coverage a tire has, because those side lugs will protect the best against sidwall abuse. This is an area that all AT's lack to a pretty large degree, and some MT's cover more than others (this is an area of road noise tradeoff).

Any tire that holds up well to serious rock crawling in this area should serve you well as the part of the sidewall nearest the tread typically takes the most abuse (pointy sticks 8" off the ground are another story, and one related more to the driver than the rubber).

 

[scottm]

When I ordered my Coopers I had to decide how many ply tire I wanted, they had different options. I don't see that now, but maybe I'm just missing it. I talked to an engineer at Cooper, they really all have the same number of plies these days, but much heavier plies are rated as more plies.

How's that for overanalyzing a purchase - I actually called and talked to tire engineers.

 

[ashooter]

I probably am over-analyzing this.

If Cooper isn't molding chicken bones and jewelry into their tires anymore, their STT would probably be pretty good since it has sidewalls with 2 radial plies and one "angular" ply... But, I have yet to hear anybody complain about a Toyo MT, so that's probably what I'll end up with (if I can find 'em). Should last longer, ride quieter, and be at least as tough as the Cooper. More expensive, but not much price difference in the size I need.

Thanks for all the input guys.

 

[Red Sox Cruiser]

I just went with the TrXus and am really impressed especially because of the price. So far the sand, mud, and rocks have all been no problem for them. Creeper Sleeper runs the Toyo's and has been fairly happy with them except for them not being sticky enough on the rocks. We ran 8 psi in the sand, we ran down to 6 psi in the snow. Aired back up to 11 to run some rock and never had an issue all day. My .02

 

[CreeperSleeper]

I just went with the TrXus and am really impressed especially because of the price. So far the sand, mud, and rocks have all been no problem for them. Creeper Sleeper runs the Toyo's and has been fairly happy with them except for them not being sticky enough on the rocks. We ran 8 psi in the sand, we ran down to 6 psi in the snow. Aired back up to 11 to run some rock and never had an issue all day. My .02

I don't know about "fairly happy"... I was when they were new! Now they "fairly suck"! Feels like I'm back on old skool BFG Muds. Sad thing is, they wear so damn well I'm gonna be stuck with these things for another year at least!

 

[Nay]

I don't know about "fairly happy"... I was when they were new! Now they "fairly suck"! Feels like I'm back on old skool BFG Muds. Sad thing is, they wear so damn well I'm gonna be stuck with these things for another year at least!

That sounds exactly like a BFG experience

Trxus rule. They wear out just fast enough to let you know you needed new rubber anyway.