If you can't lower your tyre pressure, can you at least engage 4WD!

It's at times like those that you wish you had the old Dirty Harry 44 magnum, shoot out all 4 tyres, that'll solve the pressure issue.

Don't mind educating people, as I do recall I was once an inexperienced 4WDer, but those that know better and choose not to, do annoy me.

With some it is a badge of honour to remain in 2WD.

"Yair, went right through on two wheels mate... no f- worries"
Leaving behind a damaged track for those following!

The Southern faces of Goog's Track are really badly scalloped.

But it's probably a waste of time to carry-on about it here. Those who behave in this way are unlikely to be reading it here. Or if they did, would take no advice.

A little advise please.
I don't get out too much, but I know to drop tyre pressure and use 4 WD drive when required.
But the corrugated roads have me beat. I travelled on the Rail Road from Tom Price into Dampier and also Broome to Cape Leveque. They where very bad, I dropped pressure to about 25 PSI. I was knocked around no matter what speed (or lack of). Other vehicles were passing me at ease. I was in a 2006 Hulux with a CT.
Thanks

Wato

This is a fascinating topic. The Cape Leveque road is corrugated to hell in parts. So what speed to drive at, what tyre pressure and what about cornering. The 25 psi would have been find as the trye soaks up some of the pressure. As for speed what you try to do is get the speed right so that you are skimming over the top of the ruts. This is were it gets interesting, if you are doing this, then you are partly airborne while driving. They did a test in USA and came up with the little fact that at 83km/h this was the safest speed to drive over corrugations!Well, maybe for the type they were using for the test. Not to mention tyre size (will leave this out). Your drive speed will be determined by the size and height of the corrugations as well as distance betweem each mound. On the Cape leveque road, you may find that 50km/h is the most comfortable, or it maybe 60? You have to judge this and bear in mind that the faster,than the harder the car is hitting the road and therefore more damage can occur. Remember the airborne bit, well when cornering, being airborne means no traction and therefore if you are too fast you get either front wheel skid or rear wheel skid. Both can roll the vehicle, or put you up a tree or into an oncoming vehicle. So for corners, you have to slow down. Rougher, but really worth it. As for being passed, who cares as long as they don't spray you with rocks. Not to mention that they probably aren't seeing anything. Lastly, the faster you go the worst you make them.
shane c5

Wato

You did the right thing dropping tyre pressure on corrugated roads - it will make the ride mildly softer but they will save the shockies from a lot of extra work where they might overheat and fail.

As for others passing with what seems like ease - well no they are not at ease. When some corrugations are not that far apart you can sit at 60 to 80km and get a general vibration / rattle that you might live with. I often find I don't want to destroy my car and camping gear and just slow right down. Further when traveling at any kind of speed on corrugations you run the risk of bouncing yourself off the road - you really have no grip on the road and can sort of aquaplane into the bush.

Don't worry about people (who might not even own the car) smashing it over rough roads. We were slowly working our way across the gunbarrel years ago when a range rover came other direction at 80+km barely controlling his flight. Would have done the gunbarrel in 1 or 2 days. Or not. We suffered enough damage from worn parts and we were going dead slow.

Cheers

Serendipity

Dropping tyre pressure to increase the ' footprint ' and therefore traction is one thing , dropping tyre pressure to change ride comfort over corrugations is another thing entirely , less air pressure in the tyre increases the heat of the tyre dramaticaly and can lead to premature failure far quicker than a correct spring and shock combination will fail.

Hi Watto,

Travelling on that road can be very rough. The vehicles sailing past you were probably those amazing mining vehicles that seem to be able to do incredible speeds and carry enormous loads - lol.

You did the right thing by slowing down and letting your tyres down. That way your vehicle and teeth will last a lot longer.

cheers

Very true. These are 2 different situations.
I drop my pressures down on corrugations but not to the same degree as I do in deep sand.

I soon learn't though with split rims reduced pressure on corrugations does not work real well as far as damaging the tubes due to the increased tyre flex. Works well with tubless though as there is less heat produced with tyre flex as long as you don't go too low.

Whats the best pressure? Hard to say due to all the variables involved but if you learn to "read" your vehicle you will find a good compromise for sand or corrugations.

Gady Watto,

As I think most have mentioned in inferred to. It depends a lot on what you call a smooth ride, some don't mind bouncing from one side of the road to the other. I have always found with the right tyre pressure and in 4WD not to many places that you can't find a ggod comfy speed, I exclude the Anne Beadell Highway from that comment LOL. Also it depends on the weight of and in your vehicle and also a huge part of the equation is what tyres you run, (Wall thickness and construction) being a major influence.

Wato

Working up in the Pilbara at the moment I travel the Dampier to Tom Price road from time to time, was out there last Sunday, and with my job probably spend more time on the dirt than bitumen.

A few people may frown upon what I say but it depends on how much dirt road driving experience you have and how comfortable you are driving with a bit of wheel-spin and the odd slide. I generallly drop tyre pressures to somewhere between 24-28 psi depending on how far and fast I will be going. You then get up to a speed where as previously mentioned you begin skipping over the corrugations. BUT this does reduce traction, so the vehicle will sometimes skip sideways, and give a bit of oversteer or understeer in the corners, if you are confident and comfortable in being able to correct this fine, if you have any doubts then best to slow down.

Also as previously stated comfortable is a relative thing, what some people call a comfortable ride, others may call rough. Also if you are towing a trailer or have a particularly top heavy vehicle the above is not reccommended.

Snowy

Agree with you wholeheartedly Peter. I converted my previous car (80 series) to part-time 4WD. While there may have been a difference in fuel consumption, it was beyond my ability to measure outside of a laboratory.

But the main reason I regretted the decision was the handling on loose surfaces (not just serious 4WD tracks). It was a completely different vehicle on any gravel with 4WD engaged.

Have another full-time 4WD now, and not going to make that mistake again.

Cheers,

Matt.

Interesting thing a shire engineer told me years ago not long after the 80 series GLX & Disco's with their full time 4WD became popular with farmers in his area - you could tell every single one of them that had one because the gravel road adjacent to their farm gate stopped getting corrugated, where they accelerated away.

Just proves that wheel slip is what is primarily responsible for corrugations. I remember meeting a big tagalong group on the Anne Beadell once where EVERYONE had to be in 4WD with tyres deflated appropriately and the track was completely different behind the convoy (of about a dozen) as it had been in front of it - like it had been graded.

So I'm with you Peter & Matt, my Prado, being full time was always in 4WD, but my Pajero now is too. I can't discern a fuel consumption difference in the Paj between 2&4WD on the highway. A mate who's now done over 200,000km in a similar Paj says he can't discern a difference in tyre wear either.

When I get off the black top I usually put it in 4wd and i agree that only poor simple deluded fools try to do a 4wd track in 2wd, It isn't a badge of honour its a badge of stupidity. But Id like to install freewheeling hubs on my Hilux, I use it unlocked on road when towing heavy loads down hill etc.

Cheers Wilko

G'day Barry,

When I told the guy in the Mallee that he should let air out of his tyres there was a sign 500 metres back that he had passed that said "Deep sand 4WD only".
Can't spell it out any better than that!

Cheers
Stu

Yeah you're right about the idiots who simply don't read the signs, but very few of the signs do make the obvious point about protecting the track by using 4WD.

I think there are a lot more inexperienced drivers who simply need the point being made. Even if you don't want to let your tyres down for whatever lame reason, you are going to do a lot less harm to the track in 4WD.

Trackcare don't really even emphasize how actually engaging 4WD, whether you think you NEED it or not, is a great way to protect the track.

I just think if we did this a lot more, we'd have better tracks and maybe even start to break down the '2WD badge of honour' thing that we've all encountered, usually on a chopped up track.

Another great question, corros are formed not by one process but by serval all at the same time. !) speed, the faster you go the more dust you raise and therefore the more dirt moved, 2) the road soes actually stick to the tyres for a period of time, usually nanoseconds, as the yre goes round, pebbles, quartz and the likeare picked up by the tyre and fall off in a rythem due in part to the shochies, the fall off in the grab and bounce caused by the vehicle travelling over them,, 30 the dust rised then catches on the small build up of "rocks" for the sake of the exercise which slowly/quickly builds up the mounds of dirt that form corros. The Mitchell Plateau road, actually the Port Warrender road is a great example and some of the most amazing corros you can encounter, is made up of small nodules of Iron Oxide as it is a lateritic soil, if you got out of the car, you can with a little difficulty, kick the corros over as they are just mounds of dirt. Do this with clients all the time. If people slowed down, the corros would take longer to form, but form they will.

Another but different example is coming out of creek crossings and speeding up the hill. The tyres and suspension, have different jobs. The shockies are design to keeep the tyres on the road. The drive thru the tyres, works against this and dig. So presdure is exerted thru the tyres for traction, the shockies try to hold the tyres down, but push and release the pressure causing corros up the hill. If people just cruised up the hill, these corros wouldn't form at all. 4wd is benefitial in this case. Most evident on the track into the bungles. When you go down the hill, these are a bloody nightmare.

So corros form for many different reasons, depending on, soils, speed, and terrain.
shane c5

I wish he would start fining them. Every second driver on the Steep Point Road seems to be an idiot that either wont deflate his tyres,or has to do 80klms+ all the way back to the bitumen

Ive seen signs like that before. One track I go down regularly says to deflate your tyres or cop a $200 penalty, but it really cant be enforced.
I think you would fine that none of them are legal really.............what would happen if some one had an accident and their tyre pressures were below manufactures specifications?

Cheers

for a fine to be enforced it has to be in government legislation

otherwise best they can do is pursue you for breach of contract (by entering and passing the sighn you have a contract to abide by their conditions)

They have all encompassing laws which read like "failure to comply with a notice"
I imagine its similar in the way health and safety notices are issued.
Another similar situation would be where C.A.L.M(WA) issue orders forbidding the general public to enter areas being logged to keep protesters out.

Parliament passes an Act which gives govt depts the power to prosecute.
Govts do this to save money and time by not having to invent a new law for everything.

I imagine it would also be illegal for a govt dept to put up signs saying they will fine you when no such power exists.