[QUOTE=Phil 850;3205503...the plasticisers in the rubber are forced to move around and keep the tyre flexible.Phil[/QUOTE]
It would be interesting to hear more authoritative information on this. Same with ozone damage. Let the science and engineering speak.
A shoe salesman gave me the same thing, not moving the plasticisers in the glue being why the soles on a pair of sand shoes in the cupboard for a year fell straight off when I put them on for the first time. Maybe shoe manufacturers are educating sales people on why their products appear to be crap but really aren't? The soles on a pair of German hiking boots bought in 1986, covering over 800 klms of muck, although not worn for two decades because of some foot swelling, are still stuck to the leather upper.
I have a small tractor and several old 4x4's that roll around the property. The tractor came with tyres already about 10 years old, and they lasted about another 20 years, destroyed by big sidewall rips due to tree stumps etc - without rips they would still be in use. Replaced them with exact same brand and model of tyre and I will be lucky to see 10 years judging by the cracking on all, and one with really poor melding of rubber into what should have been a cohesive mass. The 4x4's tyres on the old vehicles are probably 20 years old in themselves, but still flexible, no sign of tread separation - of course I would suspect their reliability at speed, but then I've seen worse condition on much younger tires used on a daily basis. I remember how bald you could get cross plies. On the other hand I have gone through 2 sets of tyres (10) on the troop carrier, each set no older than about 7 years, all on tar, about 85% tread - they throw the whole tread and leave you with a perfectly in tact carcass, thankfully, so you can pull over, change the tyre and limp back to town for new tyres and lose several days holiday. The tyre retailer '...yea mate, it's stone bruising...' my proverbial ar..
Myself, I think it is built in obsolescence, like they now do with pillows (date stamped) - I guess they have become part of the fast fashion culture; and like they used to do with light bulbs. Maybe poorer manufacturing in a lower wage countries with less regard to the quality of material inputs. And regulators that accept some of the guff put to them by the manufacturers. Like engines, why not regulate improvements in longevity, better performance each year, less land fill and micro plastics, and yes I understand some tyres have to be sticky and wear quicker, but overall hmmm - imagine built in obsolescence in athletes, you are approaching your athletic prime (read 'we have better science and engineering') and yet returning worse results each year, but that's good!
That's enough of my 1am rant. Off into the dark to see what's sneaking into the fruit and veg patch.
