pancake tires

[ericos_bob]

Anyone now of a good sand tire for the syncro up to a 30x9.5x15.
Almost all my driving is exclusive beach/dunes and street. I will probably run some kind of all season tire as opposed to all terrains for best performance on sand but wondering if there are any particular brand of tires/treads especially well suited to airing down and giving the biggest foot print possible. My old man kept raving on about a special michelin tire used by the army which he had on his unimog 20 years ago when crossing the sahara. Said they were unbelievable as they would spread like a pancake when the air 'pressure was dropped. Now that's the kind of flotation I'm thinking of! As far as structure goes would a tire with softer or rigid side walls be better and what about light truck tires? cheers

[syncroand101]

Your old man was probably talking about the Michelin XS Sand Tyre, I think they have been around a few years. But only come in Military Sizes - mainly 16" and 20" s..

Most the Paris -Dark competitors (when it existed) seem to use BFG Mud Terrains..

[syncropaddy]

I remember seeing these tyres in an American magazine some years ago (before the internet) and Im sure you could source something in the states. Try looking for dune buggy / sand rail stuff

[Aidan]

still available in good old 7.50R16, very land rover military, would fit a 16" and may be a jacked up 14, don't know what the radius is

[ericos_bob]

cool yep I reckon these are the tires he was talking about. I don't have 16"s on my syncro and have thrown down too much money on a set of alloys. Wish I could try these tires out. At 7.5 wide they're pretty damn narrow compared to say the 30x9.5x15s I'd first considered buying. Do they make up for the lack in width when aired down? I can only imagine that perhaps they are narrow due to them being used as an all purpose tire in which case narrow tires usually outperform excessively fat tires in all but soft sandy conditions. They are advertised as a sand tire though. Guess I could still go for a bfg in 15" size. I really didn't think an aggressive mud terrain would be optimal for sand but if they used them in paris dakar.. Was always advised a street tire would perform better. Now I'm confused

[Aidan]

not something many of us have any experience over here there are no dunes that we can drive on generally here and bugger all other sand due to it being temperate climate so unless we go to Africa , or that place in France where T'onion and co went we don't do sand; I'd go with local tyre recommendations from your country - you'll have to have a jacked up van and do body mods to fit 30.5 on a syncro

[syncroand101]

In a sand tyre, I seem to remember that you want something that elongates the tread footprint on deflation rather than widens it - ie the Michelin XS is narrrow, but on deflation spreads fore and aft rather than width ways. Which gives you the greater contact area and flotation, but still allows you to drive forward through the sand. If a tyre deflates width ways i.e. spreads out then it increases the effort in forward movement even more..

[ericos_bob]

good point on the sand resistance with wide tires. Unfortunately the michelins are way too tall to fit on a syncro after doing some searching to find out the diameter. Would like to go tall and narrow but the syncro is kind of short and wide. 235/75/15 fit fine as of current with a 2" lift and with light mods I could go to 30x9.5 which I was intent on doing though may not make an improvement in the sand as they don't have much in height on the 235s and the extra width prob isn't going to do my 2.2 subi engine favours ploughing through sand. before the 235s I did find the syncro performed surprisingly well on dunes with the 27x8.5x14 even running at 30 psi. The van was totally empty though and is now a camper about 500kg heavier all loaded up. The 235s work perfect in current beach driving conditions but are very fast wearing cheap test tires I'm looking to replace asap. Will probably just go out and get an all season tire with soft side walls for a rounder edge when deflated and see how well they go. Looks like I'll have to put a video driving the syncro in dunes up on youtube soon to show those deprived of sand another thing the syncro does well:)

[syncropaddy]

In a sand tyre, I seem to remember that you want something that elongates the tread footprint on deflation rather than widens it - ie the Michelin XS is narrrow, but on deflation spreads fore and aft rather than width ways. Which gives you the greater contact area and flotation, but still allows you to drive forward through the sand. If a tyre deflates width ways i.e. spreads out then it increases the effort in forward movement even more..

Is that true? I didn't know that but on consideration it makes sense.

[v-lux]

I didn't know that

Doesnt mean it isnt true..

[ericos_bob]

I think it is def true if I imagine it in an extreme situation. if you had a tire the size of a roller skates and it was 2 meters wide to make up lacking surface area I don't think you'd be going forward very well. A bicycle width tire with a 2 meter long footprint would move through the sand much better ofcourse if you could practicably distribute the load through it's length but how massive would the wheel/tire need to be for such a foot print? . On the other hand wide tires would add so much extra flotation that I do think they would help to a point where returns become diminishing. I mean if I ran 30x9.5x15 against a 30x7.5x15 there's approx 25% more surface area per tire. This may still offer me an advantage on the sand over the narrow set up despite the extra resistance my tires must push through to maintain momentum. On the other hand I know my syncro would probably not move a 30x12.5 even with a more powerful engine I think the resistance of the sand infront of the tires may be great enough to cause that extra power applied to dig the tire down deeper! On the other hand a taller tire of lets say 34x12.5 would roll over sand much better and the amount of power/gearing you have to deal with the size of such a tire would be the limiting factor as to how well you'd go through the sand provided vehicle weight is similar. The question that plagues me n now is what is a good ratio of tire width and height for optimum performance on sand? Anyone got ideas there or is there some kind of guide to go by?

[RichardF]

In the Ozzie desert we used aircraft tyres on our 5 ton surveying trucks, which carried a lot of equipment over very soft sand, and mud when it rained. They were run at very low pressure, about 10psi if I remember correctly, were ribbed, and very fat, so they spread out enormously. Someone said they fitted DC3s. We never got stuck, even with wheels half buried.

Don't know if any aircraft tyres fit VW wheels....

[ericos_bob]

Aircraft tires? Interesting indeed. I like your thinking I will definitely have to dig around on the net on that one and see what pops ups! cheers

[ericos_bob]

Found a site with aircraft tires a plenty to fit our syncros. http://www.airecy.com.au/TyresList.html
I highly doubt there's any way you could legally use an aircraft tire on the street but would be great for rec sand driving

[syncropaddy]

Found a site with aircraft tires a plenty to fit our syncros. http://www.airecy.com.au/TyresList.html
I highly doubt there's any way you could legally use an aircraft tire on the street but would be great for rec sand driving

Looks like fun?