Tyre roll over rim

[Meken]

Deflated the 255/50/20's down to 28 for my sojourn up duck creek rd. I was taking it pretty easy as had the trouble & strife in the passenger seat panicking about how close to the edge we looked, and tin lid on back getting bounced around in his booster seat.... Need I say more? Anyway thanks to my tardiness in keeping the weeks polished I can clearly see where the tyres were folding over the rims... Quite a bit in places.
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[rar110]

Interesting. I went down duck ck rd recently. I was surprised how deteriorated it's become. It's become more of a 4WD challenge track than a viable alternative way to O'Reilly's. There was slot of traffick going up. I drove up that rd in my Corolla years ago. It wouldn't get far now.

I was on 255/55/19s. I didn't deflate tyres.

[rhinosm]

Recent trip East West across Simpson.
On Duratrac 255/55/19
I had tyres on 30psi for Birdsville Track etc.
Deflated one to 28 on the to 25psi and stopped.
We didn't feel confident, it didn't look good.
Put them all back to 30psi, no issues.
Being my first experience in this type of driving maybe we were being too cautious.

[Disco-tastic]

I have 255/60/18 HT's and i only deflate to 30 for rocky terrain even at that pressure i have pinched the sidewall multiple times and had air escape once (I thought I'd popped it!).

They are HTs though so a very soft, flexible sidewall

Cheers

Dan

[laughto]

I left my tyres at Highway pressures for the trip to Jim Jim Falls (about 110k of corrugated road) and the Old Jim Jim Road (similar). Mostly on 70 - 80kph in most parts on both roads. A little bouncy, but no issues. Gets a bit 'floaty' above these speeds. Not sure deflated tyres would make difference to this, but for me seemed to be little point, particuarly as it would just expose the sidewalls to potential hazards.

Sent from my SM-G920I using AULRO mobile app

[ozscott]

The idea of lowering pressures off road was, apart from extra grip from longer footprint, was to allow the tyre to deform around rocks and roots protecting the belts from more severe impacts from sharp objects . Cheers

[Chops]

Looking at the pics, you'd have to say that 28's way to low on a 20" rim.

[LandyAndy]

Looking at the pics, you'd have to say that 28's way to low on a 20" rim.

The tyres have a rim protector,ie the tyre bead protects the edge of the rim,its pretty normal for them to rub on the rim when deflated.
Andrew

[Meken]

Max speed was probably 25 (was in low range) - no I don't think too low - I run them down to 17 on sand. They are Pirelli scorpion m&s

[Bytemrk]

I left my tyres at Highway pressures for the trip to Jim Jim Falls (about 110k of corrugated road) and the Old Jim Jim Road (similar). Mostly on 70 - 80kph in most parts on both roads. A little bouncy, but no issues. Gets a bit 'floaty' above these speeds. Not sure deflated tyres would make difference to this, but for me seemed to be little point, particuarly as it would just expose the sidewalls to potential hazards.


Dropping the pressures a little would certainly help iron out the corrugations a little.. but would also require less speed.

One thing I think is a danger in these cars, is the air suspension does such a good job, it insulates the driver from just how hard the car is working underneath.

Last year in outback SA on the track to Lake Cadibarrawirracanna and then again on the road out to Halligan Bay, I found I could easily sit on 80 - 90... while I was getting messages from those in defenders and a 101 that they were being rattled to pieces and needed to travel far slower.

Nice to have that comfort and a car of that ability.... but I see a risk of not being mechanically sympathetic enough in places you really don't want to break something if you're not careful.

[Celtoid]

"One thing I think is a danger in these cars, is the air suspension does such a good job, it insulates the driver from just how hard the car is working underneath".

I totally agree and I think a tyre monitoring system is a must when travelling.

When I got to the critical failure/puncture point on D4 number 1, on my OEM supplied Wranglers (~40K), I got three punctures in one week. All of them stones through the tread pattern. The car was heavy as we were camping but driving on nothing more than Forestry tracks.

On the way home a wobble became apparent but it was windy and I had roof racks on. I pulled over and checked the car. A tyre had a slow leak and looked like it was at about 10 psi. The side wall of the tyre had been almost cut off and must have been seconds away from a blow out. I recon with less load and less wind I could have been driving on my rims and not known.

[cripesamighty]

Mark, you are quite right about the cars being maybe a bit too comfy for their own good. Gordon mentioned that at his seminar I attended where he said it was a trap for new players. You can definitely hammer these cars to a breakage without realising it. Mechanical sympathy is important at the best of times but possibly more so in these cars as they just ride so well.

[ozscott]

Tyres used to be part of shock absorption...

Cheers

[rar110]

Tyres used to be part of shock absorption... Cheers

That was one reason I went to 18s.