Thread: Sand Driving

Originally Posted by trout1105

I would think that the difference in the amount of "Flex" that the higher profile tyres have would be negligible on sand.
As long as you can lower the pressure enough without popping the tyre off the bead the 20 inch rims should do the job as long as the actual wheel height is the same on both sizes of rims.

Until you hit a rock etc at pace...

Or, you bounce, and pinch rim and Tyre...

Originally Posted by Tombie

Until you hit a rock etc at pace...

Or, you bounce, and pinch rim and Tyre...

Like I said in Sand the 20 inch rims should be OK, On rocks definitely Not so good.
Regardless of what size/type of tyre you are running, Hitting a rock at speed will test them all.

Originally Posted by Celtoid

Yup, unloaded a D4 is heavier than all of the Defenders standard. I looked into this ages ago so I'm rusty on the numbers ... I think a Deefer can legally carry more load bringing their weights in at pretty close to/or heavier than a D4 depending on the model (110 - 130) when in camping mode :-).

Yes a 110 is about 520kg lighter..

However it places significantly more pressure on the ground (in standard trim) than a D4 and is noticeable on sand..

A trimmed Defender, even not packed for a trip will run around 2,500kg+ without even trying...
(Draws, Bar, Towbar, rack, steps etc)

Originally Posted by Tombie

Yes a 110 is about 520kg lighter..

However it places significantly more pressure on the ground (in standard trim) than a D4 and is noticeable on sand..

A trimmed Defender, even not packed for a trip will run around 2,500kg+ without even trying...
(Draws, Bar, Towbar, rack, steps etc)

Dont worry Tombie im basically sold on a D4.

I dont understand what your saying above though.

Point 1 above- Your telling me that a half ton lighter car is putting more pressure on the sand?? How.
I measured the contact patch of my 235-85-16 conti's with only 1mm of legal tread.( replacing the set next week) at 16 PSi which is what i run on sand and its just over 295mm with my bedding , tools and empty fridge in the back and 2/3 of a tank.
so a 255-55-19 on a D4 at 15 psi has a patch of 275mm and the tyre height is 43mm less. Its width though gives it a cm more each side so contact patch is basically the same area but 2cm wider not longer and therefore will push more sand. My new tyres will be even longer
Point 2 above- I bought my 110 from interstate and had to take it to a weigh bridge before registering it in NSW. From memory it was 1995 kg. I then put my camping gear in and go away. Actually i remove the back seats making it even lighter! Ill put the same camping gear in a D4 .
If you want to talk "trimmed out" as you say with winches and bars etc which i dont have then surely you would then add that to the D4 also or are you trying to compare a expedition ready 110 loaded to its legal limit to a D4 off the showroom floor?

Just got back from a 3 day trip mostly on sand. South Coast of W.A is notoriously soft, the first dune proved that there is no point going any higher than 12PSI as the sands that soft not one car made it up on 18PSI. Went to 12PSI R and 10PSI Front and made it up first time, Calcup Hill was first attempt too (1km high dune going up in 2 long stages).
Was pretty glad I had 18" wheels for this trip though as I wouldn't fancy driving around on 10PSI for 2 days with any less sidewall.

Timax,

With a D4 a lot of gear also removes weight whilst adding it - so a front bar takes some significant weight off whilst adding a bit more... where as the Defender bar weighs almost nothing compared to what gets added.

The pressure equation is force over area, so assuming contact patch length stays the same and width increases there’s is less pressure per square (insert cm or inch).

Think of it like a a knife - would you want me to apply 20 psi of pressure on you arm with the flat side or the sharp edge ?

I've had 2 D4s since Jan 2010. I got GOE 18s (and run Zeon LTZ 285/60/18s) after maybe a year or so of ownership of the first D4. As I go on the beach a lot less often than I'd like, I usually stay on my Road Shoes and do a quick swap out before going on a trip.

I did Fraser, Bribie and Moreton several times with the standard sized 19s (OEM supplied Wranglers and then Pirelli Scorpions ATRs). Both performed pretty well but are much less 'flexible' (figuratively speaking) than the 18s. On Both Fraser and Moreton I've had to go below 18 psi because I was getting close to bogging a couple of times. But then you run the risk of tyre damage when you hit roots (especially Fraser). You just don't have a lot of tyre between the rim and the obstacle.

It can be impractical to keep stopping to change pressures to suit if the terrain varies a bit. I just drop the 18s to 16 psi and never really have to worry. There is enough sidewall to be stress free if you cross rocks or roots at a sensible speed and they will probably fare OK if you hit something by surprise when travelling a bit faster. They also have no issues in most soft sand conditions at that pressure even going uphill and then having to pull up a berm to let the Prado passed that can't climb said berm .... even downhill ... LOL!!! (back of Tangalooma).

I just drive through most things without thinking about it now and obviously have more pressure options if the going gets really tough.

Kev.

I'm just back from a 9500km trip to Cape York with a 2 week stop over on the way home on Fraser Island. Tyres are std 255/55/19 size.
Only time bogged was powder dry sand up the Cape I was not prepared for and did t have DSC off and it went down. That's fully loaded , full pressure and with Camper on the back.
For Fraser we dropped the tyres to 18 on the D4 and 15 on the camper for the run through Inskip Point but it wasn't needed. Once on the island I ran 24 for the rest of the trip with no problems.
Tyres are the Hankook RF 10 and they had 40k on them before the trip. They were fantastic, no punctures and handed all sorts of conditions really well.