Tyres, low pressures and stiffies

[Gascoigne]

G'day all.

In situations where tyre pressures need to be lowered such as driving in sand in particular, has anyone got any thoughts on or experience with whether tyres with stiffer side-walls are an advantage or a disadvantage?

I've got Goodyear MTR's on and, as I understand it, they have relatively stiffer side-walls than many other tyres. (Please correct me if I'm wrong on this).

On the one hand it's been suggested to me that:
- more rigid side-wall = less flex when aired down = less heat build-up

On the other hand I have heard that they could be more prone to develop splits with prolonged low-pressure travel on sand.

Does it matter:confused::confused::confused:

Much appreciate any thoughts.

Cheers

Gascoigne

[Pedro_The_Swift]

Its seems its the length of the tread foot print that makes the difference when you deflate tyres,,

I think a bulging sidewall would add width and be just one more thing to push through the sand,,

[Xtreme]

Its seems its the length of the tread foot print that makes the difference when you deflate tyres,,

I think a bulging sidewall would add width and be just one more thing to push through the sand,,

Absolutely correct.
A large diameter tyre is far better in sand than a wide small diameter tyre.
The larger diameter tyre will also give a far better ride in the bush.

This however has little to do with the 'thread' - low pressures and stiffies.
One of the biggest killer of tyres is heat, therefore, low pressures, high speed and excessive flexing should be kept to a minimum.

[Zute]

In my experience with MTR's they "bag" easily. Low profile tyres(70>) Bag less because of the cross section. Have a close look at a truck tyre and see the foot print they have. A good sand tyre would be 80 profile.
I think a softer side wall will always be better than a stiffer one, because you can run a higher pressure with less danger of rolling the tyre off the rim. Finding the right pressure for your tyre, type of rim and weight of fourby is the trick. My brother runs MTR's on his Sportage. 24psi is as low as he can go with the mag wheels he has. My Zook with Kumho MT's I can run at 10psi with no trouble.
Running a tyre under inflated will create more heat. That's why you should drive slower and check them more often.

[isuzurover]

In my experience with MTR's they "bag" easily.

Agree - I have 285/75/16 (33") MTRs on the IIA, and they bad very easily. I run them at 8-9psi when doing "serious" 4x4ing, but I have them on fairly narrow rims. Have never had a problem with heat or lost a bead. At that pressure they stick like glue to anything!

Sometimes they stick too well!
https://www.aulro.com/afvb/

[Cap]

Your kidding me Ben, they stuck a large rock like that and jammed it up there! Thats some serious grip!

[isuzurover]

Your kidding me Ben, they stuck a large rock like that and jammed it up there! Thats some serious grip!

I kid you not! That's my IIA - happened while I was driving one of the ex-comp tracks at Janowen hills 4x4 park. Took a high-lift and a lot of effort to get it out!!!