On Sat, 10 May 2008 22:33:31 -0500, Sarah Houston
<SHoust@pndfnospam.com> wrote:

>I'm wondering if these guys are just trying to sell me a new tire, or
>what?
>
>One of my snow tires looked a little low, so I took them all in anyway to
>get swapped out for the summer tires today and asked them to check it, and
>fix it if necessary.
>
>They said it was a nail in the tread, but being it wasn't in the very
>center of the tread, more towards the outside of where the tread meets the
>road, that the tire is "unfixable" and I should buy a new one ( from them
>) next fall.
>
>Is this true or just a trick they may use on gullible women?

No, it's mostly true, but in the 'consumer driver' world they have
perverted it into a good excuse to sell replacement tires.

If the hole is in the sidewall or the transition area in the first
inch of the tread, those areas flex a lot as you drive.

Either the patch fails to stick over the long term, or the steel and
fabric tread belts inside the tire start to fail - a few strands get
cut by the nail, and if you try using a plug repair the reamer and
insertion tools cut and damage more. And then the flexing from
driving snaps more belt cords, and eventually catastrophic failure.

This is NOT a sure thing, but it happens often enough that they make
the blanket recommendations to trash every tire that it could happen
to - if they don't and someone dies, they're on the hook for millions.

If you want to take the liability, you can have an internal hot-
vulcanized patch applied, just like your old fuel-tab bicycle patches
but updated. Go find a tire shop that specializes in industrial and
farm tires, they know how to fix them instead of automatically
condemning them.

The hot-patcher for car and truck tires looks like a one-sided
electric waffle iron married to a huge C-Clamp. There's a double-
sided clamp for sidewall patches where they use a little filler rubber
inside the gash like chewing gum, and need to heat both sides to cure
it. The patches for tire sidewalls have their own fabric plies inside
the patch, looks like a big Band-Aid - mostly meant for farm implement
tires where they don't want to throw out a $500 tire with a sidewall
gash that isn't nearly worn out yet, but they'll work on car tires
just as well.

That, or they do make inner tubes for radial tires.

And whether patched or tubed (or both) you mark the sidewall so you
know it's the patched tire, put that tire on the rear where failure is
less critical, and you inspect that tire often. When belts start to
rip and fail inside the sidewall the stresses try to redistribute, and
the tire will usually start showing obvious odd bulges and depressions
on the outside before it lets go - if you know to watch for them.

This is precisely why they don't want to patch them - 99% of drivers
don't check things like tire pressures and conditions even monthly (or
at all), they just get in and drive. (Till it fails.) With a cheesy
tire, you want to do this weekly at least.

--<< Bruce >>--