Tyres on sand

[Scrambler]

I'm putting forward a theory here and anyone can respond. I'm ok with being wrong.





This was my tread pattern on an ex-army Land Rover I took to Fraser on my honeymoon. The tyres are 7.50R16 or 190.5/100R16 if you prefer metric. If the car had Army bar treads I'd have taken them so I'm not arguing the logic of it only the outcome.

We ran about 16psi, soft sand and hard. We were towing a trailer.





No bogging, no spinning.

I don't think lack of aggressive tread is an issue in sand: assuming its not dune buggy racing.

The theory: low pressure (long footprint) is everything on sand regardless of tread.

[Dicko1]

Tyre pressure is more important than tyre pattern. I used to visit many Aboriginal communities that involved at least 5 klm of very soft sand that was often only uncovered at low tide. The tojos/patrol utes with box fitted on back were sevearl hundred kilo over legal weight. We had standard rims and Dunlop road gripper tyres. I,d let tyres down to 15-20psi and 99% of the time had no hassles. Got bogged once or twice but let more air out and proceed slowly. Road pattern tyre give more surface area cover but can be lacking in the bush/offroad. I,d recommend a good all terrain with pressure adjusted for the terrain/sand and you should have no problems. Never carried max trax or the like and the places we went were far more remote than what 99% would experience.

[dean]

Pictures ? if so can't see them.
We used to run skinny cross plys decades ago on 2wd's that could get through some horrendous sand to get to surfing spots.
Anyway nowadays you choose between GAS and KISS....back then only KISS existed.
And yes pressure is far more important than tread.
Dean

[old Jack]

A thread and the linked threads a worth reading;

https://www2.pajeroclub.com.au/forum/showthread.php?t=28809

1. Footprint length is everything, and this is related to the tyre pressure, the overall diameter of the tyre and the tyre sidewall height.
2. Footprint width has very little positive effect and sometimes a negative impact especially if gearing is too high and power/torque is insufficent.
3. Smooth treaded tyres are best on trailers and other non-driving wheels but as soon as the wheel is driven then an aggressive tread pattern will get you further especially in soft sand and when climbing dunes, but this same aggressive treaded tyre will dig down and bog you deep if you do not get off the accelerator quickly once you have lost forward or rearward movement.


OJ.

[Scrambler]

Pictures ? if so can't see them.
We used to run skinny cross plys decades ago on 2wd's that could get through some horrendous sand to get to surfing spots.
Anyway nowadays you choose between GAS and KISS....back then only KISS existed.
And yes pressure is far more important than tread.
Dean

Thanks. Not sure on the pics: there's 2 that came up ok on my pretest post and appear on mine. Will add links in a bit.

[erad]

Having wide tyres is sand is not a good idea. Reason is that you are bulldozing or compressing a wider band of sand away than if you used narrow tread tyres. If you drop the pressures, the tread 'flat spot' increases. Whatever you do, it is still a function of pressure which is a force per unit area. The force is the weight of the vehicle and the area is how much area is required to support that load, so whatever sized tyre you have, you will still spread the load over the same area. It is just the shape of the contact pattern which varies. A narrow tyre displaces less sand sideways and therefore it requires less power to move the sand.

My second car was a 1963 Cortina. Very light - 16.2 cwt dry (without petrol, coolant etc). I used to go to Mt Baw Baw skiing every weekend, and all my friends had VW's. A VW with wintertread tyres will climb a tree, but in snow 1 ft deep, the wheels used to droop down until they ran out of suspension travel, and the VW would then stop. My Cortina had Michelin tyres on it, and it used to leave tracks in the wet snow about 1" deep. I would drive past the VW's and gloat about how good VW's were. Then I bought a Triumph 2000 - Independent rear suspension, Pirelli tyres - this was going to be unstoppable. Wrong - the first bit of snow I came to it just stopped. it took me years to sort that one out - heavier car, wider tyres were definitely NOT the way to go in the snow. I imagine that sand would be the same conclusion. Nowadays, you have to fit chains as soon as it looks like being cold, so it is irrelevant.