Heading to the Landor races soon. Tow vehicle and van are fairly close to maximum weights and have tyres on tug on fairly high pressures for the sealed roads. When I hit the gravel do you lower tyre pressures all round even if there are no corrugations? Also is 80kph the maximum you can (should) reach on a fairly good well graded road? Thanks.
Landor races
- Thread starter Gero
- Start date
It depends on the condition of the dirt road surface, no hard rule really because some dirt roads are in better condition than a sealed road........... most damage is done to vehicles on dirt roads because folk want to go flat out, too high pressure will shake things to pieces while too low and too fast you can easily loose control, stake the sidewall is the big issue, the one hard fast rule is drive to conditions....... While I may drop a few psi, ambient temp plays a part, I prefer to drop the speed as well ......
Learn how to read the dirt so you can spot the soft spot, loose gravel etc a big wide dirt road often means there will be bull dust holes, so not ideal to go flat out ................
Back in the days of having to select FWD I would hook up the front diff and drive in High 4, towing or not was always the safest way.....
Learn how to read the dirt so you can spot the soft spot, loose gravel etc a big wide dirt road often means there will be bull dust holes, so not ideal to go flat out ................
Back in the days of having to select FWD I would hook up the front diff and drive in High 4, towing or not was always the safest way.....
Last edited:
When towing I don't drop the tugs below what it would be solo and the van only a few psi (5 or 6) if it's corrugated prefer to drop the speed otherwise you have to pump them back up again.... In the truck I would just slow down the rougher it got too many tyres....... Hope the weather is kind...be sure to be plenty of boy racers throwing rocks around.
Last edited:
I almost always drop my tyre pressures. For moderate corrugations it's 25psi cold all round except for rears in tug which are 28-30 cold. Greatly reduces tyre and caravan damage in my experience. Also drop speeds to less than 70kmh
Tyre size, construction and weights need to be considered along with what psi you normally load them with in the first place but dropping by half wouldnt be a good idea at all., at 25psi my vans would run off the rim and the Jeep at 30 would end up with the sidewalls ripped out........... My van runs at 47 and the Jeep at 45 rear on the sealed road (towing), so if let down for dirt I'd drop probably 4 psi cold, depending on the road surface ..... The differences in tyres is huge so the psi you use is your choice, never use what someone else advises unless you know the tyre type in question............ My tyres are LT265 75R16, ATR's they have a max pressure of 80 psi while others are smaller and have max pressure of maybe 45 psi, so it pays to know what your tyre is capable of and never run at max psi.....
Vans should have LT tyres then you have a greater variation in psi and the tyre placard is a guide for the original tyre once you change tyres the placard becomes irrelevant and correct pressure on sealed roads is always 4-6 psi above the cold pressure no matter what is said in a book or label...... so on dirt 4-6 psi below cold is a rule of thumb with a drop in speed, as it gets rougher then I get slower , I hate opening the tool box.....
The thing is, what has been loosened on the dirt may not show up until miles later when you are banging down the highway, so a proper check when parked up of the rig is essential, boots and a rubber hammer seem to do the job, sounds over the top but I rarely have to stop and fix things..
Vans should have LT tyres then you have a greater variation in psi and the tyre placard is a guide for the original tyre once you change tyres the placard becomes irrelevant and correct pressure on sealed roads is always 4-6 psi above the cold pressure no matter what is said in a book or label...... so on dirt 4-6 psi below cold is a rule of thumb with a drop in speed, as it gets rougher then I get slower , I hate opening the tool box.....
The thing is, what has been loosened on the dirt may not show up until miles later when you are banging down the highway, so a proper check when parked up of the rig is essential, boots and a rubber hammer seem to do the job, sounds over the top but I rarely have to stop and fix things..
Yes mine have a max. of 65psi and I run them at 45 psi. (Dual axle) I worked it out from an online calculator that i think you may have recommended in the past Drover. From memory you commented on how a lot of caravaners have too much pressure in their van tyres. Correct me if i am wrong. My van use to seem to bounce along before i dropped the pressure to 45 psi.
About 50psi hot so 45/46 when cold. Same in ute rear and 40/42 hot in ute fronts. I have LT tyres so those pressures don't bulge out the sides a huge amount. Re Drover's comment, I do limit my speed to 70kmh at lower pressures. Heck I've been down to 12 in the van trying to cross soft sand but each tyre and load is different
The only time I had major tyre damage on the last trip was running road pressures on the 'well maintained' dirt road wiluna to meekatharra . My wife has instructions to never let me do that again
Quite possibly could have, while I found that online calculator handy I did have to adjust the pressures to get things just right, the compliance plate on mine says something like 38 psi and Big mal wallows down the road ..................................... I have seen some rigs bouncing as they motor down the road as well as some walking sideways as the sidewalls lay over from lack of pressure, I think the best test is the old check pressure once warm to be 4-6 psi higher than cold, then you find the right one for the ambient temp at the time ............. even though its 1 psi rise for every 10 deg ambient it seems like they rise more.
Nowadays I stay clear of most corrugations so dropping down 5 or 6 psi seems to be okay along with a relative speed drop, then if teeth rattle let out some more, no hard fast rules its all a decision taken for the conditions. ...................
Heck on the Surat Development Road, which has been under development for some 90 years I was down to 40kph for long stretches and its sealed, would have stopped and let some air out actually but no where to pull up........ never bluddy again.............
Back from landor races. Dropped tyre pressures by 5psi initially and got puncture in Kennedy ranges which is very rough with lots of sharp rocks. Had just purchased a tyre repair kit which I used for the first time. All the rest of the roads to landor and Mt Augustus were actually very good and by this time dropped tyres to 30psi and averaged 70kph. Most people I spoke to had pressures of 25 to 30 psi. Left van at 45psi. Tug tyres are nearly at the end of their life so will check out options for new ones. Now only have to get the red dust out of everything! Although van is pretty good considering.
Actually lied about using tyre repair kit as a young couple helped change the tyre and showed us how to use it. Meet nice people when travelling in remote areas.