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View Full Version : Tyre Pressure for soft sand/beach driving



bradleyfutter
08-03-10, 10:39 AM
Hi all,

Went out to Stockton beach on Saturday. Was great fun, first time I've been driving on soft sand and the dunes.

Started out letting my tyres down to about 22 PSI at Lavis Lane. got down onto the beach and got stuck trying to get over that first big hill to get down towards the surf, well didnt get stuck just couldn't get over the dune, so dropped it to 18 PSI. i noticed that even at 18 PSI the tyres didn't seem to bulge/balloon much at all? I'm just scared of letting them down to much rolling them off the rims !!

Ive got Mikey Thompson's ATZ 31x10.5R15 on my TJ, what sort of tyre pressure would you recommend for soft sand driving? Ive used the search function to try and find other posts on tyre pressure but it kept saying it didn't find any? which i find hard to believe?

thanks for the help,
Brad

Steve F
08-03-10, 11:05 AM
You're typically not making sharp turns on the sand or running very fast, these are the things that will cause the tyre to roll off the bead (or obstacles, not many of those on the sand either though) I run my Maxxis Bighorns (32x11.5x15) down to about 12psi on the sand, not much will stop it at those pressures, you'd be surprised how much easier it'll get around compared to 18psi, or even 15psi. Those few less make a huge difference.

Cheers
Steve

Hunno
08-03-10, 11:29 AM
I run at 15 PSI on the track & 12 PSI on the sand. Hunty said on the Lake Lyel trip he runs at 10 PSI on the track.

Jaffas
08-03-10, 04:27 PM
Last time I was at stockton (a while back) I think I ended up dropping my tyres (goodyear MTR 33's) to about 9psi. even at 12psi I found the XJ to be working really hard and the temp gauge getting toward the red, but at 9psi it was happy as larry.

Really, the lower the better on sand, but just take it slow, drop it a few pounds at a time and find what works for you. Micky T's are a pretty decent tyre with good side walls, so will probably handle lower pressures quite well. So next time you there, try 15psi for a while, then 12psi. I don't think I would go much below that on a 31. (bit more room to play in a 33).

Good luck!

Hunty
08-03-10, 05:57 PM
I run at 15 PSI on the track & 12 PSI on the sand. Hunty said on the Lake Lyel trip he runs at 10 PSI on the track.

Hi Guyz
Shush hunno I don't want cop an inevitable truck load of discontent from those who think im crazy running down to 10psi -LoL

Ok Heres my thoughts on TP
My 07 JK Jeep without roof doors and rear seats is a lot lighter than some (would be a heap lighter without me also - LoL)
so I let my tyres (Light truck MTZ's) down depending on conditions and load - on sand I go down to 10psi and sometimes 8 or 9. - but I am also very careful not to turn to fast and peel the tyres of the rims (very easy to do @ 10psi) - & for those of you who like embarrassing Nissan Toymotas - my kids on their L plates have driven up to them stuck in the sand and backed up to them and snatched them out - its no magical 4x4 or secret - they are on road tyres or AT's and they feel they have let them down enough (22psi) and wonder how is it that a Jeep with L plates on..........

On rough dirt roads with sharp stones and at cruising speed (80kph) 18 - 23psi - anything less and serious tyre damage IS likely not to mention loss of control of the vehicle due to decreased steering response or worse still, you peel the tyre from the rim whilst cornering and crash!

On rough dirt roads with steep difficult terrain and large rocks (that my tyres could slip on) slow navigating in low range 10 - 15psi

I am always very cautious below 15psi for anything that could stake a side wall and consequently I usually run 12.5 - 15psi - Hunno caught me running 10psi on the lake lyel run as I did not want to loose traction on any of the steep hill climbs (no diff locks yet)

I determined these pressures on many runs on Stockton beach and at the Wattagans (these suit my light 2dr JK with stiff side wall Light truck tyres)

The first time I ventured below 15 on the JK I was on Stockton beach and was watching for side wall ballooning - so I let down the tyres 1psi at a time and tested the traction improvements - as you all know on Sand the bigger the tyre foot print the less the engine has to work and the easier and further up the sand dunes you can go!
below is a pic of my JK on Stockton with 35's AT - I purposely did'nt drop the pressure at all (35psi) for 2 reasons
1. too lazy and didnt want to pump them back up
2. Test whether or not my JK could do sand on 35's at road tyre pressure

result - I did make it on to the beach, ran around a heap and yes I made it off - but take a look at the trax they are fairly deep, I noticed significantly higher levels of engine power required! - as soon as I slowed down I could really feel the Jeep bogging in. - However on 33's MTZ's and with pressures down my JK actually rolls along the beach with considerably less effort. - I often come across stranded 4x4's on the beach and the common fault is OVERHEATING from working their engines too hard (not deflating appropriately their tyres)

In conclusion I suggest a lot of testing and proving - watch the side walls of the tyres as you deflate, it is very obvious when they are too flat. beware that the lower the tyre pressure the better the grip but the more susceptible the tyres are to damage. I can not stress enough the dangers of decreased steering response when lower pressures are used and the increased likely hood of destroying your expensive rubber
cheers Hunty


http://i685.photobucket.com/albums/vv217/ashunty/beach35s.jpg

Wooders
08-03-10, 10:12 PM
My rule - if you haven't popped a bead you are rulling too much pressure ;)
But I do recommend always carrying a compressor & having practiced the techniques to reseat a bead, for when you do pop one.

Also on sand drop the pressure a bit lower (IMO 12-14PSI would be about perfect for a TJ on 31"s), and try not to make hard fast turns and the bead will probably be fine.

Another thing to remember - the sidewall bagg is not a true indication of how much air pressure is in the tyre and the real gain in traction is due to the increase LENGTH in the tread pattern not the increased width.

Jaffas
08-03-10, 10:23 PM
Another thing to remember - the sidewall bagg is not a true indication of how much air pressure is in the tyre and the real gain in traction is due to the increase LENGTH in the tread pattern not the increased width.

What he said

Hunty
08-03-10, 11:17 PM
My rule - if you haven't popped a bead you are rulling too much pressure ;)
But I do recommend always carrying a compressor & having practiced the techniques to reseat a bead, for when you do pop one.

Also on sand drop the pressure a bit lower (IMO 12-14PSI would be about perfect for a TJ on 31"s), and try not to make hard fast turns and the bead will probably be fine.

Another thing to remember - the sidewall bagg is not a true indication of how much air pressure is in the tyre and the real gain in traction is due to the increase LENGTH in the tread pattern not the increased width.

Cheers Dave - I totally agree - you should Know how to safely reseat the bead and once you learn how to do it safely - then you can do it with fire! LoL
step by step instructions
1. Get your compressor ready and connected to the tyre valve (switch it off but be ready to activate it in an instant)
2. squirt anything flamable into the tyre - I use "start ya bastard" or Butane (lighter gas)
3. get your head and limbs as far away as possible and light the flamable stuff, pray you get it right or prepare your will and kiss your sweet ass good bye!
4. 2 milliseconds after step 3 turn on compressor
see YouTube video
cheers Hunty


http://www.youtube.com/watch?v=hL76Dt_epLA

Hunty
09-03-10, 11:39 PM
Thanx Steve for embedding the video - it looks great embedded - my next project is to improve the interior lighting in my Jeep and I'm thinking of a Blog - what do you think? - I plan to use a heap of pix similar to this 1 - cheers Hunty
http://i685.photobucket.com/albums/vv217/ashunty/DSCN0937.jpg

Hunty
10-03-10, 08:15 PM
Hi Guyz
Shush hunno I don't want cop an inevitable truck load of discontent from those who think im crazy running down to 10psi -LoL

Ok Heres my thoughts on TP
My 07 JK Jeep without roof doors and rear seats is a lot lighter than some (would be a heap lighter without me also - LoL)
so I let my tyres (Light truck MTZ's) down depending on conditions and load - on sand I go down to 10psi and sometimes 8 or 9. - but I am also very careful not to turn to fast and peel the tyres of the rims (very easy to do @ 10psi) - & for those of you who like embarrassing Nissan Toymotas - my kids on their L plates have driven up to them stuck in the sand and backed up to them and snatched them out - its no magical 4x4 or secret - they are on road tyres or AT's and they feel they have let them down enough (22psi) and wonder how is it that a Jeep with L plates on..........

On rough dirt roads with sharp stones and at cruising speed (80kph) 18 - 23psi - anything less and serious tyre damage IS likely not to mention loss of control of the vehicle due to decreased steering response or worse still, you peel the tyre from the rim whilst cornering and crash!

On rough dirt roads with steep difficult terrain and large rocks (that my tyres could slip on) slow navigating in low range 10 - 15psi

I am always very cautious below 15psi for anything that could stake a side wall and consequently I usually run 12.5 - 15psi - Hunno caught me running 10psi on the lake lyel run as I did not want to loose traction on any of the steep hill climbs (no diff locks yet)

I determined these pressures on many runs on Stockton beach and at the Wattagans (these suit my light 2dr JK with stiff side wall Light truck tyres)

The first time I ventured below 15 on the JK I was on Stockton beach and was watching for side wall ballooning - so I let down the tyres 1psi at a time and tested the traction improvements - as you all know on Sand the bigger the tyre foot print the less the engine has to work and the easier and further up the sand dunes you can go!
below is a pic of my JK on Stockton with 35's AT - I purposely did'nt drop the pressure at all (35psi) for 2 reasons
1. too lazy and didnt want to pump them back up
2. Test whether or not my JK could do sand on 35's at road tyre pressure

result - I did make it on to the beach, ran around a heap and yes I made it off - but take a look at the trax they are fairly deep, I noticed significantly higher levels of engine power required! - as soon as I slowed down I could really feel the Jeep bogging in. - However on 33's MTZ's and with pressures down my JK actually rolls along the beach with considerably less effort. - I often come across stranded 4x4's on the beach and the common fault is OVERHEATING from working their engines too hard (not deflating appropriately their tyres)

In conclusion I suggest a lot of testing and proving - watch the side walls of the tyres as you deflate, it is very obvious when they are too flat. beware that the lower the tyre pressure the better the grip but the more susceptible the tyres are to damage. I can not stress enough the dangers of decreased steering response when lower pressures are used and the increased likely hood of destroying your expensive rubber
cheers Hunty


http://i685.photobucket.com/albums/vv217/ashunty/beach35s.jpg


Hi Guyz
just to add a couple of pix to reinforce my warnings re extreme low pressures - its funny cause its a Toymota - LoL - ouch I guess thats a bit harsh
cheers Hunty
http://i685.photobucket.com/albums/vv217/ashunty/4x4_licolatodargo131_0912311929.jpg
http://i685.photobucket.com/albums/vv217/ashunty/4x4_licolatodargo130_0912311928.jpg