On my previous Pirelli P3s, which had been on the car for many years, I
nearly bought the ranch. Just before going out on a high-speed section of very
dangerous highway (Highway 17 from Scotts Valley to San Jose for you Bay Area
people) I noticed the feeling of a little ripple under one wheel. For whatever
reason, I decided to check it out and discovered that the sidewall and tread on
the inside of the wheel had already parted company in several spots and the
tire was just about to completely delaminate.
In any number of discussions I've had since, including researching a piece on
wheels and tires for an upcoming Sports Car Market, I've had the technical
experts tell me that (a) all tires age, regardless of care ---though they do
age
faster in extreme conditions or under extreme driving. (b) they age from the
inside out and in many brands of radial tires, that means that the portion
between the tread and sidewall deteriorates first -- as mine did. (c) the
inside
of the tire -- closest to the dirt and heat under the car will show the extent
of wear much sooner than the visible exterior and (d) that as the rubber
ages, the rubber becomes harder and less resilient.
Is five years, or six years, or ten years the magic number for replacement
regardless of appearance? I don't know, but I do know that I avoided a serious
accident once on ten-year-old tires that should have been replaced, have
started to see wear (sidewall checking) on the inside portions of my current
six-year-old Dunlop SP20s, and when I put a "brand-new" set of tires on my race
car
that had been sitting on the shelf (in a dark, climate-controlled warehouse)
for five years, they were worse than useless, with almost no effective grip
compared to the newly manufactured set I replaced them with. As Alan says -- a
nything else goes wrong, you ride home with Bubba. Your tires or wheels go, you
are much more likely to ride to the hospital with the EMT.
So, folks, I'd suggest you look carefully at the inside surfaces of your own
tires, starting about five years into their life, and when they show any
extent of wear, replace them. On cars you buy, you don't know how the car has
been
stored or driven, so regardless of the appearance, if there's reason to
believe the tires are more than four-five years old, start to think about
replacing
them.
For heaven's sake, you can get a set of Kumhos from Hendrix for very little
money, and they're excellent tires. Why even argue the point when for less than
$200 you can be sure you're safe.
Cheers
gary
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