Tyre pressure

[1tuf75]

How low can you go?
with out bead locks,
whats the lowest pressure you can go with out risking rolling off the rim and tyre/rim slip ?
im mainly wanting to know for steep loose terrain and maybe at times mud, some cornering but only at low speed.
i drive a 75 series ute with 33" muddies

[Mick.]

It really depends on lots of things. :-\

1. The tyre your running because some side walls are thicker than others meaning the thicker the side wall the more air can be let out. The thinner the side wall the more more the tread will flatten out without as much air needing to be removed.

2. The weight you will be carrying. The more weight you carry the more chance of rolling tyres off the rim.

3. The terrain you are driving. If driving on cross slopes you could run tyres off the rim more easily than if driving on flatter surfaces.

4. The speeds you are doing. If you going really slow than this isn't as much of a problem. If you are driving at higher speeds to say get to one track from another than you wouldn't want to let your tyres down to far either.

It's really all about trial and error. Start out by letting a little bit of air out ( around 10psi) and see how you go. Than go from there.

Most people without bead locks run there tyres anywhere from 12psi to 20psi but it's all really trial and error. ;)

Cheers Mick.

[Peter @ Aawen4x4]

If your vehicle is bogged on the beach below the high tide mark and the tide is on its way in, you can go as low as you need to in order to get it out!! If that means ZERO pressure and stuffing the tyres, what've you lost?? Save the investment in the vehicle, but you might lose or damage irrepairably the tyres!! I know what I'd be doing, and bugger the cost of a new set of tyres (unless I could figure out how to get the insurance company to kick the $$ in to replace the vehicle and all it's accessories!?)

A tyre at 0 psi, with gentle accellerator and steerng input, can actually get you a fair way on ultra soft sand, mud, and snow; but the further you go the more damage you do to the inside of the tyre! If you've got Second Air Beadllocks, it helps a lot, and the 0 psi option is not such a worry!!

Have Fun!!

[MudRhino]

It may be of benefit to you to know that I have found - as others I know have too - that BFGs M/T under 22psi tend to get crap in the beed and ultimately leave you with flat tyres.

You may want to install tubes - as these act somewhat like a poor man's beed lock.

[Peter @ Aawen4x4]

Just be careful with tubes, and keep an eye on them, 'cos when you run low pressure tyres AND tubes, the tube (and tyre casing) can slip around the rim as you work the tyres, eventually pulling the valve stem OFF the tube, and dropping you into the sh#t with no way of repairing that particular tube. You also need to make sure that the inside of the tubeless tyre has had EVERY sticker and raised mark inside the casing ground off, and doing this removes most of the airtight skin that keeps air from bleeding out thru the rubber when used in tubeless mode. If you don't do this, the tube will rub on the sticker or raised bit, and create a friction hole, quite large usually, and often irrepairable too!

I eventually gave up on the tube idea, and went back to tubeless. I'd been having so much trouble with tubes pulling off valve stems or rubbing thru on a trip that I pulled the tubes out half way across the Simpson! Then I found out about the inability of the tyre to hold air effectively once the skin on the inside had been disturbed!! BUT, Goop or tyre slime is wonderful stuff, although you've got to be prepared to throw the tyre away afterwards, 'cos NO-ONE will ever clean it out!!

[1tuf75]

thanks for the replies so far im currently running 33x 12.5x 15 nankang muddies most of the driving i wanted to know for is steep and shaley rock there are the odd step that make you bounce abit but other than that just slippery usually loaded to the hilt with gear too which proly doesnt help much im about to get a compressor so ill play around a bit carrying 2 spares i just wanted to know in case i really got stuck. the track im talking about leads me into one of my favourite hunting spots unfortunatly its the BEST of the 4 tracks that lead out of the gully i shattered a free wheeling hub about 2 months ago halfway up and had to walk out all up hill too.

[sudso]

It may be of benefit to you to know that I have found - as others I know have too - that BFGs M/T under 22psi tend to get crap in the beed and ultimately leave you with flat tyres.

You may want to install tubes - as these act somewhat like a poor man's beed lock.

I've got 33"x 15 BFG MT's, bought them second hand on rims with tubes in em, The guy I bought them off said BFG themselves recommend tubes if you are going to go lower than 22psi with these tyres. I've removed the tubes as they are a tubeless radial anyway And for the reasons Peter A mentioned but I've yet to test them below 22psi.
Besides I dont use em on soft sand where you really need low pressures.

Wish second airs were'nt so damn expensive, can get a set of tyres for that!

[grimbo]

I have 33 x 10.50 BFG muds and have regularly run them at 16psi in sand and snow under my GQ. Never had a problem with crap in the beads etc. You just have to be careful and inspect them before and after re inflating.

On my Zuk I hve run the 34" Swampers as low as 3psi without any beads, only rolled the tyre off once but that was when I forgot I had them down that low and was punting through the corners on a windy dirt road at a bit of speed, no ownder the steering was heavy. Just a quick blip with the compressor and all was good again.

The best advice is to experiment, just make sure you have a compressor handy

[mudpiggy]

I have run my BFG A/T's at 15psi all round heaps of times and they love it.

[tariadamar]

i have had motorway remoulds (they came with the car)

1. off road lage rocks run at like 25psi and up

2. in ruts run like 30psi as the turning will force it off

3. mud depends on the ruts if you are struggling if thier is some one else and if their are lage rocks but i found about 20- 22 psi was good.

4. on sand i was able to run 16 psi which is good as the beads where stuffed

this is just a guied from what i do you will most likly be able to go lower but this would be a great starting point.

[crawla]

this is a while back but I remember doing Porters with a fella who deflated his swampers (35x14.5x15 if I remember correctly) to 5 psi with no beadlocks. They worked a treat. That WAS a rock crawling track. He was running them on his shorty 40, what a great looking tyre. I ran 33x12.5 muddies on my cruiser a while back and the lowest I ever went was 16 psi. I also had a detroit in the rear. I drove similar terrain that you are driving (mud, steep forest tracks, rock crawling) and never ever had a drama.

[Patrolman Pat]

I've had my MT/Rs down to 10psi on the beach and no problems with them at that pressure.

[ravofireman]

Just be careful with tubes, and keep an eye on them, 'cos when you run low pressure tyres AND tubes, the tube (and tyre casing) can slip around the rim as you work the tyres, eventually pulling the valve stem OFF the tube, and dropping you into the sh#t with no way of repairing that particular tube. You also need to make sure that the inside of the tubeless tyre has had EVERY sticker and raised mark inside the casing ground off, and doing this removes most of the airtight skin that keeps air from bleeding out thru the rubber when used in tubeless mode. If you don't do this, the tube will rub on the sticker or raised bit, and create a friction hole, quite large usually, and often irrepairable too!

I eventually gave up on the tube idea, and went back to tubeless. I'd been having so much trouble with tubes pulling off valve stems or rubbing thru on a trip that I pulled the tubes out half way across the Simpson! Then I found out about the inability of the tyre to hold air effectively once the skin on the inside had been disturbed!! BUT, Goop or tyre slime is wonderful stuff, although you've got to be prepared to throw the tyre away afterwards, 'cos NO-ONE will ever clean it out!!



well if u do decide u buff away the stickers and bumps in the tyre to stop tube rubbing u should put a linner selant back over it,, dries smooth and wont worrie the tube,,,,,,

[DGR01]

we compete on boggers at between 8-12psi and no beadlocks, but we sikaflex the beads on!!

its a cheap easy way out. the next step is to bead screw the rims, you could do a full set of rims for $20 ($6 drill bit and $10 for short self tappers). Most drag cars runs screwed beads.

so no excuse for not doing it, average joe could sikaflex and screw a full set of rims in 3 hrs and for under $50 at home.

[Grantlington]

i can run my coopers at 10psi without beadlocks and its still fine. Havent had a trye pop off yet.