Deflating trailer tyres on sand

Grunter
I remember seeing a post on it months ago, but 25 on the 4x4 is still to high I reackon, 20 with lockers, 18 without.

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Here's what Jol Fleming has to say about it..........

Tyre pressure

Drop them its does make a difference.
The biggest source of drag with the Jayco will be that it has a wider track than the tow vehicle and must cut its own track, its can't follow the vehicle tracks, the drag in any soft terrain will be huge.
BTDT

Hey Grunter65,

we have a goldstream camper and when ever we tow on sand which is normally about twice a year we deflate the camper tyres to 18 psi the same as the car, we never use to deflate the camper tyres but through trial and error have found it is much easier if we do.

Pmacks

We do a lot of Towing on the Sand, I usually drop the Tyre Pressure
down to 18 to 20 psi, now towing your Jayco you will notice that
the Wheel Axle width is wider than your towing vehicle track, which
means your wheels on the Jayco don't track the same as your tow vehicle, they have to make there own track, so the lower the Tyre
Pressure, the wider the Surface Pressure on the sand,
Trailers with to much Air Pressure tend to be Dragged through the
Sand, rather than Riding on top of the sand.
Some of the other Forum Users might be able to explain it better.

Cheers
Daza

I drop my trailer tyres on sand.
They do bag out, and they don't 'sink' into the sand as far, so must be less work for the car pulling it through.

Normally run my trailer tyres about the same or a bit less than my Paj front tyres.

Interesting,
On fraser and other places I drop my tyres to 25 on the diesel paj too.
Is a bit high, but when you are doing 70 to 80km/hr on the beach, the tyres don't get too hot.
I drop the tyres to about 20 for the really soft stuff. Thats 20 on warm tyres and will go lower if needed.

What tyres you running on the paj? Mine are 10 ply LT 235/85/16.
(Do more trips out west than on the beach.)

Yep - we always lower the pressures on our Campomatic trailer when those on the car go down - makes basic sense to me and agreed re Jol Fleming's vast experience mentioned above - he has done heaps of sand driving with a trailer....... and once those tyre are down, we take it very easy due to those sidewall bulges.

I always let the tyres down a little on the trailer.. normally down to around the 25psi mark.. unless the sand is really soft then let them down more..

The "proper" way of doing it is to let the tow vehicle tyres down and measure the length of the foot print and then let the tyre down to match (assuming the tyres are the same diameter)

What I usually do is a bit of a compromise as I don't want the camper to be too soft on tyres that are down when I am in it of a night etc.. so I usually just let them down a bit and if the going is tough let them down a bit more..

It really does make a noticeable difference to the towing ability.

Yep always deflate to about the same as the rear of the 4x4 thats what rule we use and yoy can always let more out to see what happens in the real soft stuff.


All the best
Eric

The best answer to these questions comes from the tyre manufacturer's data (if you can get it).
I run Michelin 305/70R 19.5 XDE2s on the OKA.
Michelin provide pressure Vs speed Vs load data for these tyres, so there is absolutely no guessing.

What becomes apparet though, when looking at the data, is that the appropriate pressure has a linear relationship (approx) with the load. ie: if the tyre has a max load of 1000kg at 60psi (HIGHWAY speeds), the appropriate pressure for a load of 750kg is 45psi (3/4s of each).
Used according to these tables, every tyre with different loads will have different pressures, but the shape and footprint of all tyres will be the SAME.

At lower speeds, all of the pressures are lower, but the load/pressure relationship remains the same.

Michelin actually quote load/pressure tables for:
1. Highway speeds.
2. Dirt (65kph)
3. Sand (20kph)

If you EXCEED the speeds (or the loads) for the pressures that you are using, the tyre overheats and fails.

I use the same data for trailers as I do for the vehicle.

Cheers,
Peter
OKA196 Motorhome

we just took a group of 5 caravans over to fraser island about a month ago, personally i don't let my caravan tyres down cause i have rebuilt my caravan and set it up with the same wheel track as my cruiser. on this trip i had a mate who took his 16ft jayco expander over there and he let his tyres down on the caravan, bloke working on the barge suggested he pump the tyres back up which my mate thought was odd. once we hit the harder sand my mates van tendered to wander due to the lower tyre pressures (which is what the barge worker said would happen), he stopped and pumped them back up and never had another problem. so i think in soft sand low tyre pressures help, but on the harder stuff it is better to have them reinflated.

HI , i also have the Jayco Flamingo Outback - when i go onto Stockton beach i let ALL my tires down --- i have my Stauns set to 15 PSI- have a Nissan patrol and the tire tracking seams to be the same between trailer and tow vehicle

it really does make a difference in the way the van tows in the really dry soft sand.... i see people come straight in of the tar onto the soft sand , full noise and struggling in the soft stuff ( no trailer or anything- not letting tires down ) --- and i just cruise in with very little effort - some even look surprised as they see me coming in as the flamingo isn't exactly small as you would know ....

On a side note -- i had a tire EXPLODE on the jayco last weekend - sounded like a gun shot - followed by a fairly good whip sending me across all the lanes on the freeway ( was doing 100KMH at the time ) a quick look in the mirrors shows all the motorists behind me taking evasive action not to get showered in pieces of rubber .. managed to get it straight and drove it out - then limped to the nearest bay --- spare only had 10 PSI and my air pump has been killed from the week before - and of coarse the only time i didn't have a pump on board was the one time i needed it ( always have one onboard)

anyway - long and short - didn't know the age of the tires -- all pressures were good ( 40 PSI) so i replaced all the tires on monday with brand new coopers - guessing age was the main factor -

Boc

(photo is from my phone - sorry for quality)

P.s these were not recaps