Tire/Tyre Science..

["therealdmcvegas" <DMCVegas@xxxx>]

--- In dmcnews@xxxxxxxxxxxxxxx, PRC1216@xxxx wrote:
> From what I understand, driving on NCTs is still fine as long as
they have been out of sunlight and have been siliconed over the years.
The only two things that detiorate rubber tires are UV Light and
Ozone, NOT Age. Applying silicone/eagle 1 tire shine/whatever should
prevent the Ozone from destroying the rubber (dryrot). Look around
the outside of the tire for cracks, and you know the tires have not
been cared for. New tires are still the best option, but some NCTs
are still very useable.
> 
> Patrick
> 1880 "88NGONE"

Please take note: This isn't an attack againt Patrick, or anyone else
who still uses NCTs. It just some facts, and a bit of speculation at
the end.

Yes, it is true that the two most damaging, non-road hazard factors to
tires are UV & Ozone. And to compensate, tires feature built-in
measures to protect themselves from these detrimental influences. But
both measures technicly can be used up, and can cause a *technical*
shelf life, that is determined by how said tires were stored. So while
there is no >exact< experation date of when you should stop using the
tires, you can extend their life. But they still can go bad over time.
Tires really don't so much "dry out" when they rot, but the rubber
compound decomposes.

UltraViolet Light Damage:
Rubber is naturally gray coloured, and carbon polymers are added into
the formula to make the rubber black. Black of course is the best
color at absorbing heat & UV. And the carbon in the rubber will absorb
the UV, and convert it into heat to be disappated, and thus the rubber
is saved. But the cost of this protection comes at the sacfirice of
the carbon in the rubber. So over time, the carbon protection will
wear out. The only way to truly extend the life of the UV protectant
is to store the tires in a COOL DARK enviornment where they are never
exposed to light. Simply covering the tires with blankets isn't good
enough. You've got to make sure that the coverings are both UV
resistant & protect UV from penetrating thru, and that the they also
cover the inner sidewalls as well. Light can after all reflect under
the car.

Ozone Damage:
Ozone is another damaging element to rubber, that will also break it
down. And to combat this, a wax polymer is added into the tire
formula. Ozone is created when oxygen encounters arcing electricity,
such as lightning. So anything from light switches, to relays can
generate ozone. However the biggest ozone generators that threaten
tires are almost unavoidable when it comes to cars: And that is
flourescent shoplights! The ballasts used not just to start the lamps,
but to continuously operate them continuously generate steady amounts
of ozone. The good news is that as your tire rotates down the road, it
of course flexs. This allows the wax to gently secreet out, or
"bloom", and replenish the outer coating. Anyone who's ever worn
natural leather shoes has seen this same thing. The more you walk, the
more the natural animal fats in the hide rise to the surface as the
leather strecthes and flexes. Anywho, the wax compound as you can
guess sacrifices itself too in order to protect the rubber from the
damaging effects of ozone. But just like the carbon additive, it too
has a finite amount the will eventually exhaust itself.

However, this protection will only work on a car that is driven
regularly. Because after all, you must flex the rubber in the tires,
to force out fresh wax to replace what has been stripped away by ozone!

Extending tire life:
Yes, as stated before, you can extend the life of tire rubber. But you
must be VERY care as to what you use! Petrolium distillates are BAD!
They end up stripping the protectants on the surface, exposing the
rubber, and acellerating the deterioration. As I have seen on many
websites, use only water-borne polymers, siloxane or amino functional
dressings when cleaning/protecting rubber surfaces on a car. This goes
for tires, bumper trim, door seals, etc... These types of products
will allow you to not only to acheive an orignal shine, but you'll
also maintain it, and coat the rubber surface with an additional layer
of UV & Ozone protectants. You just have to let them dry before usage
so the protectant coatings will proply ahere to the rubber. This is
the opposite of heavy petrolium distillates, and other types of
damaging dressings. They reccomend that you drive the car asap, in
order to for the centerfugal force of the tire spinning to sling the
crap off as quickly as possible to actually minimize damage (but
screwing up paint surfaces of the car, and wheels in the process).

Safety:
Old tires are NOT safe to run on. If you've got a car that you trailer
everywhere, and use for competition/show purposes only, that's one
thing. Considering what one can pay simply for 6-12 months worth of
insurance, a set of brand-new tires is perhaps on of the best
investments in safety, and protection that you can get. Yeah, I'm sure
that you can extend the life of the NCT's, but why bother? The risks
involved are FAR MORE expensive than what a new set of tires costs.
The NCT's use decades old, out-dated technology. I don't care the
Goodyear happens to still use the same tread pattern a 3 obscure
tires. The NCTs present a danger with their old technology, and their
unreliable condition. Just because they look good doesn't mean that
they're truly safe under the surface. Remember the Firestone
Wilderness A/Ts? True, this was due to a manufaturing problem, and not
age. But the possability for damage to your's and other cars is the same.

Another VERY dark aspect to this is the link that David Teitelbaum
provided. If attorneys are starting to see legal cases where tire ages
are blamed as a factor, several forgein car makers are instructing car
owners to replace old tires, and even the British govt. is instituting
laws forbidding the sales of old tires, then that should sure as hell
be a warning sign to get those old tires off ASAP!!! Lawyers are
looking for someone to sue, and tire and car manufacturers are looking
to avoid getting the blame, that would leave only one person liable:
The owner of a car that had those old tires. Give it time, and these
types of regulations will eventually become law. Safety first: You
don't want to hurt anyone else out there on the road, any more than
you'd want to wreck your car. And you certainly wouln't want to get
charged with criminal negligence if you simply have a blow out on the
road. Even if it's not due to age (I once wasted a brand new tire that
had less than 30 miles on it when a nail punctured the sidewall on the
freeway, and fishtailed like hell all over before even braking!), I
would be seriously concerned about the legal ramifications 20 year old
tires could bring down on me. After all, you may not be physicly
impared, but if your BAC (Blood Alcohol Content) is beyond the *legal*
limit, then you will be charged with DWI, and perhaps even
responsability of a collision, even if you didn't cause it. So if
you're in an accident with NCT's, whos to say that fact alone couldn't
be twisted to your opponents advantage against you?

In other words, don't be cheap. Scrap the NCTs, and move on. There is
absolutely no reason, nor excuse to keep them in service.

-Robert
vin 6585 "X"