Posted by Larry Hoover on April 10, 2005, at 11:45:21
In reply to Anyone know anything about tires?, posted by KaraS on April 9, 2005, at 22:44:08
> I had to get a new tire yesterday. I was on a crowded LA highway when my front left tire ripped apart and I was suddenly driving on my rim. I was very fortunate to not have been hurt at all. (I thought that the tire had a slow leak and I was going to check into it that afternoon but unfortunately it decided it couldn't wait for that.)
If a tire is visibly down, its pressure could already be less than 50% of what it ought to be. Low tire pressure causes tires to over-heat, and then they disintegrate (or catch fire).
It's the flexing of the tire that causes the heat build-up. As the tire goes around, it has to drastically change its shape from the more normal appearance of the part not close to the road, to the more flattened pancake shape of the part bearing the car's weight. Excessive side wall flexing causes the rubber to separate from the steel radial bands that give it strength.....you're suddenly on the rim, as bits are flying around.
> Anyway, I found what I thought was a good place to buy one (relatively good prices, high rating by the BBB), purchased the new tire, they put it on and I drove off.
>
> The problem is that I remember reading in my car manual and hearing from others that it isn't good to buy just one tire, that you should also replace at least the other tire in the front (or back if that's relevant). I can't afford another $140 (I couldn't afford the first $140.)There are two relevant factors to consider, and both relate to how worn the new tire's partner is now.
As a tire wears, it changes diameter. It gets smaller. Maybe not noticeable so, but the difference can be measured in tread depth (remember that pi rČ relationship?). That can affect alignment, and effort required to turn the car (it will want to turn away from the bigger tire easier than the other way).
Also, traction itself might substantially differ, if the older mate is quite worn. In an emergency braking situation, that could make you spin. The effect is magnified on slippery (e.g. wet) roads.
> I also think I remember that the last time I got a tire replaced, they rotated the tires around. They didn't do anything like that this time. Should they have?
If you have to go with mismatched pairs, it should be on the rear.
> Am I doing more harm to my car in the long run by only replacing one tire and not rotating any of them - or are these things not that important and blown out of proportion by the manual and the tire sellers?
They are important, but the magnitude of the importance relies entirely on how different the two tires are.....the old one which pairs with the new one.
> I barely have the energy to take care of myself these days, let alone worry about this kind of crap. Anyhow, any help here would be appreciated.
>
> Thanks,
> KaraI've given you the information, you need to make a decision about what you have to do (or not).
You might get a better deal on an almost new replacement tire at a wrecking yard.
I'm sorry that sh*t happens.
Lar
poster:Larry Hoover
thread:482207
URL: http://www.dr-bob.org/babble/social/20050408/msgs/482350.html