Tuesday, Sep 08, 2020 at 07:56
Thanks for your input Gbc. Whilst I cannot categorically state that the tyre was not 'over-inflated', I do not believe this to be the case. I ran the rear pressures the same as I had the previous set of D697's from which I got 60,000kms, without that sort of chipping damage. However it is fair to say that the current tyres have seen a fair bit of rougher, rocky roads & tracks. When I blew a 10 day old tyre coming out of
Mornington Wilderness camp, & got it replaced at Nev's 'Over the Range' tyre place on the GRR, first thing he asked me was what pressure I was running. 42psi - he told me the sidewall damage had been 'just bad luck' as he considered the pressure appropriate for the weight & the conditions. 42 psi was the 'hot' pressure. Cold was 36 psi. As far as speed goes we know we have a lot of weight, & are very conservative with our speed, we don't have schedules to keep & we are slow. I can (& have) drive all day at 20kph when needed. Even on the bitumen we rarely average more than 80kph. The other factor is that the driver side rear wheel, run at the same pressures, whilst a little chipped, is nowhere near as bad as the one in the photo.
Since writing the above paragraph, a little light went on in my head! :) I recalled that when the blown tyre was replaced on the GRR, that the new one obtained there went onto the drawbar of the Tvan, & the unused one which had been on the drawbar was put on the car. It was the rear passenger side wheel. So I did a bit more checking.
I checked the dates on the Tvan tyres & the badly chipped one on the car. All the same 2014 date! I had thought they were younger than that. So the chipped tyre is 6 years old, & I suspect that this is why it has been more damaged than it's 2019 counterpart on the driver side rear. Rubber that has hardened. The part worn 2 spares we have carted around the country for the past couple of years , untouched during that time are 2013! The more I think about it the more I think the majority of the chipping damage occurred fairly recently, most likely on one particular weekend where we towed the Tvan up some long, steep & very rocky tracks in the hills west of
Mareeba, around Irvinebank.
I also checked my records. Since new tyres were fitted in
Broome we have covered 15,000kms , so a bit more than my estimate of 12,000. The tyre in the photo had done perhaps 700kms less, so not a major difference to my earlier estimation.
So whereas I was thinking that new tyres were going to be needed in the near future, I now think it best to replace all the 2014/13 ones before any further remote area trips. With the spare from Nev's place, on the Tvan also a 2019, I think the following replacement strategy probably makes the most sense, safety-wise & economically.
Remove the 3 x 2019 part worn D697's from the car & put them on the Tvan (including one as a spare).
Buy 5 new tyres (probably Toyo M55F's or RT's) for the car (including one spare) & keep the current 2019 Tvan Spare as the second spare on the car. This does mean that it may be possible at some point to mix tyre brands on the same axle, not something I would usually do, but as a fallback second spare option to get me out of trouble it doesn't seem unreasonable.
Thoughts anyone?
I should add that the process of writing in this thread itself has been a useful part of the process & I thank all who have contributed.
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