Light truck tyres dont bag out much either but bagging lengthways is the most important anyway (and LTs dont go for that much either).
Cheers
Light truck tyres dont bag out much either but bagging lengthways is the most important anyway (and LTs dont go for that much either).
Cheers
Boat: Seafarer Vagabond
Live: Great South East....love Moreton Bay fishing
But, side wall bulge means that your tread is getting longer. If it doesnt bulge then your not getting much length.
G'day,Originally Posted by flatzie
I've been reading the responses with growing concern.
Your 265/75R16 are passenger rated tyres. They are not off-road tyres. From memory I had the same size on my 1997 Pajero and the OE was Yokahama Geolanders. They drove all over Moreton Island with six up and the rest of the car full of as much gear as we could fit in and it never faltered, albeit driven carefully and gently.
I did not lower the tyre pressures. The manufacturer's plate and the owner's handbook did not specify lower pressures therefore if I had I would have been unroadworthy and uninsured. Passenger rated tyres will not tolerate lowering pressures. The sidewalls are not strong enough. They get fat (not long) and they overheat and neither of these conditions is helpful.
It is important that you understand and obey your owner's manual and the tyre placard fitted to the car. If you don't you are unroadworthy and uninsured. If you want to fit alternative wheels and tyres you will have to get an engineers certificate for the modification and apply to Queensland Transport for a modification plate and then tell your insurer.
The Triton should be up to driving on sand on standard tyres but with a much less aggressive tread. I would recommend the Geolanders for this but they are useless on crumbling rock ledges and in mud. They are durable as well if the car is drive quietly. The Pirelli Scorpion tyres are available in an off road tread and a highway tread. For sand I'd use the highway tread but they may not work in mud and may cut up on rock. If the Pirellis are a dual purpose tyre you may be able to drop pressures a bit but anything under 22psi and you risk breaking the bead between the tyre and rim.
Regards,
White Pointer
White pointer mate you are taking an extreem interpretation of the situation.
In QLD (which has possibly the strictest alternate tyre polocy), there is a reasonable amount of freedom to select alternate tyres and rims, without recourse to having them engineered.
Diameter +15mm -26mm, and more increase in width than a sensible 4WD person would want as long as you don't fiddle with the track too much.
Outside of those recomendations, there is very little room or provision to have tyre recomendation engineered in QLD
Information on these matters can be found on the QLD transport web site.
In other states, there is a great deal more feedom in modification of suspension and tyre matters.
There is in fact a national manual on what alternate wheels and tyres are appropriate for what vehicle.....QLD is stricter on the matter.......but the manual exists and tyre shops would use it on a daily basis to select alternate wheels and tyres
Considering that it is normal and reccomended safe practice to reduce tyre preasure off road, I find it very hard to believe that too many insurance companies would fail to cover you with reduced tyre preasure in an appropriate situation.
If you are concerned, make enquiries of your insurance campany....if they wont cover reduced tyre preasure off road, its time to change your insurance company.
As for cooper discovery ST not being an off road rated tyre......UM.. I think Copper would have things to say about that.
The cooper S/T 265/75R16 is only offered in a light truck carcase
Indeed the discription of the tyre , agrees with the problems encountered....it is a 10 ply rated tyre so will be quite stiff... and it has "sharp shoulders designed to dig".
So it would probaly be a very good rock and hard dirt tyre.
quote
The Sure Trac is ideally suited for carrying heavy loads on outback roads, with sharp shoulders designed to dig so you'll find they perform exceptionally well in mud and adventurous 4WD tracks.
Cooper are very forward in detailing how and when to reduce tyre preasure and the benifits...they publish a tyre guide that is free for the asking and an extensive amount of media material on the matter.
If you are talking tyre ratings, What matters is that the tyre is rated sufficient for the load being carried......some of the manufacturers offer the same tyre in the same sizes with both pasenger and light truck carcase.
You can not simply look at the profile signature on a tyre and tell its class or load rating...you need more of the information off the tyre, or from the manufacturer.
Some people who do a lot of sand driving will reject a higher load rated light truck tyre in favour of an appropriately rated pasenger rated or a flotation style tyre, specificaly because the side walls are softer.
As for the tyre getting hot......all tyres will get hot and overheat if run at excessive speeds while at reduced preasure.....this is why every single article or video clip on the matter makes a very strong point to reinflate to normal road preasures before running on sealed roads ot at increased speeds.
On the matter of perelli Scorpions...they offer a very wide range of tread patterns and and carcase types, ranging from low profile high speed highway passenger tyres thru to full blown mud terain on a light truck carcase... abit of an over generalisation on the perellis there.
There is a very big difference in running a tyre at 90 to 110Kmh on sealed roads and running a tyre at 60 to 80Kmh on sand or other off road surfaces even more so when the speed is reduced to "responsible off road speeds"
At any reduced tyre preasure there is always the risk of rolling a tyre off the bead, regardless of tyre...that is why you drive accordingly....hell its possible to roll a tyre off the bead at full preasure if you do silly things...that is whay some of the old school blokes insist on running tubes.
Reducing tyre preasuer is the recomended and responsible thing to do off road, It can considerably reduce tyre damage and damage to the tracks.
cheers
Its the details, those little details, that make the difference.
..........
Last edited by ric; 14-01-2010 at 11:05 AM. Reason: double posted
This has been an "interesting" and humerous read.
Firstly there is a HUGE difference in tyre performance on and offroad between 15 and 18psi. If your struggling at 18 PSI, i am certain lowering to 15PSI will do the trick.
Be wary though, because you have lowered your pressures to 15PSI you will no longer need to attack soft sand at high speeds, you are now able to go much slower, safer and be in more control, reducing the chance of rolling a tyre off the rim.
The only time you will roll a tyre off the rim is if you make sharp turns, so if you drive with some common sense, this won't happen to you.
WIDE VS NARROW
If you have lots of power, by no means get the extra wide tyres. but if you run a naturally aspirated diesel etc, then narrow tyres are the go for you in sand. You need far less power to push a 9" tyre through the sand than a 12". That being said, even though you are reducing the contact area with the narrower tyre, you gain more power and will still easily tackle soft sand with more comfort than being constantly underpowered with wide tyres.
The 'bagging out' of the side wall is NOT what gives you the extra traction. the extra traction is derived from the elongated contact area which reduces the ground pressure and the tendancy to sink/dig or bog in soft sand.
Each vehicle has a certain rev range which is ideal for economy and power output. Find out your rev range and use the gears of the vehicle to keep within the range when driving in soft sand.
You can usually use 5th gear at 100km/h as a general rule for finding your optimum revs to power output.
ps. I drive a turbo diesel triton with 450nm/150kw and 265/75R16 bfg all terrains
Regards, Ric
Gees...all this tyre talk makes the sand work seem hard.
We have an old SIII Landy with 43 and 1/5th hp 6 cylinder motor and black tyres (I think they have white writing on them...does that help??) with unknown tyre pressure (the white rims don't hit the bitumen anyways) and go up the beach all the time.
Should we be getting bogged??
I'm a bit worried now that we're going to have to use the wench to get us unbogged.
I intend on living for-ever....so far so good
I have done tens of thousands of km on the beach with troop carriers dating back to the early 80's.
The best tyre I found was the Bridgestone 604 pattern Desert Dueler.
These tyres also dont have steel in the sidewalls so the sidewalls can flex really well without fear of delamination.
I used to get 80000km out of them and did 3 round Australia trips including Gibb river rd and many others like it.
My trye of choice.
Black ones perhaps?
At Heaven's gate a soldier stood,
his story ready to tell,
St Peter said, 'no need my son all is understood,
Go right in cos you've already served your time in Hell'
I should have taken a photo up at Bribie yesterday. Coming past the lagoon to the cutting it looked like the tailor were on - cars everywhere. As we got closer it became apparent that the entire beach was blocked with bogged cars. I'd presume they were all within 'manufacturer's tolerances' because they were down to the chassis, and all the owners were busily letting the 'insurance' out of their tyres so that their cars didn't become artificial reefs as the tide rose.
What a mess - all because they were too LAZY to let their tyres down before attempting the beach at high tide.
If keeping your tyres within manufacturer's tolerances is a priority, then perhaps your mindset is better suited to playing golf rather than beach driving.
We're buggered..We're really buggered......they have white writing as well as the black bits.
They'll just have to remember to pump them back up again when the breakers are breaking into the quarter glass if they let the air out too late.
Well said too by the way
I intend on living for-ever....so far so good
When I was over fraser. The barge guys came and checked out my truck. They told me that over christmas time the track from the road to the barge at inskip was really powdery and soft. And that some guys with good set up trucks where pulling people out/through for $50 a pop. Made a couple of grand a day he recons. I think its wrong... But serves themselves right.
There was this little jimmy behind me and he politely asked me to keep an eye on my mirror and if he gets bogged can I pull him through. But he didnt... aired down tyres...
There was how ever 2 4x4's towing trailers and a camper that where bogged. And I snatched them out in 2wd on 10 psi. On another note the turbo diesel didnt go too well. Didnt really impress me at all. My 4.5 petty had more power down low. I attempted to pull a tour bus through indian heads and it just bogged down hard and all this pure black smoke started pouring out my exhaust. I had to abandon it due to damaging my engine. Really pissed me off.
ps. Guys who dont air down their tyres on the beach and get bogged because of laws etc are just wankers. Their the same as these fools who buy a new 4x4 and take it bush and recon it can go anywhere in standard form.
My turbo diesel navara has the same issue down low. I have read around that this is programmed to reduce emmissions. Dont know how true it is.
Mines not computer controlled, cruiser 1HDT. But it was hurting alright... Seriously, my 4.5 petrol vession wouldnt cough and choke and you didnt have to rev the tits out of it. Dont like it at all. Intercooler/ new turbo with boost from idle/lpg or flog it and ls1 it.
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