Got a flat tire on the front of the Fiesta ST. Saw the low-air warning light and limped about a mile to the nearest station. Topped it up, drove to work with no issues. Came out after work and it was 100% flat. I assumed a nail or something that caused a slow leak, but the tire shop didn't find anything. They are claiming wear on the shoulder of the tire.
I know the outside of the tread is a little worn from autocrossing, but nothing severe to my eye. I only have about 5,000 miles on these tires with 6 autocrosses. And the last autocross was months ago. Could I have worn them out that fast? (Bridgestone Potenza RE050A)
Are you on the stock alignment? Insufficient negative camber can really nuke the outer edge of a front tire when autocrossing. (It also makes you really slow) Of course "sufficient" negative camber can nuke the inside edge when you aren't autocrossing, so . . .
Shoulder wear is not a reason for a flat tire. They need to look harder for the leak (valve stem, cracked rim, bead leak) and go ahead and flip the tire now.
Tread wear, unless it is to the cords, will not cause deflation and maybe not even then.
check the valve core. I had a tire go soft. I couldn't find a source of the leak.
On a whim I checked the valve. Tightened it nearly a half turn.
No leaks since.
I think that is what happened here. My hypothesis is this: I had a leak somewhere, maybe valve stem, maybe small puncture. Either way, since it is a low profile tire, I didn't really notice it was low. When the low pressure warning light finally came on, it was probably in fact, completely flat. I drove about 3 miles to the nearest station once the light came on, assuming it was just low. Even though it aired up and drove the rest of the way to work, the damage had been done. The inside of the tire was full of rubber shavings, and the shoulder of the tire was shredded in a few places. Regardless of how it happened, it is toast now. And no warranty coverage is going to help that.
Sadly, the law in PA is that you must replace all 4 tires so that you have a matching set. And that a tread wear rating must be 200. That's the law, right guys? Right? (my wife is listening, speak up) See honey, I have to buy those Star Specs...
pinchvalve wrote:
Sadly, the law in PA is that you must replace all 4 tires so that you have a matching set. And that a tread wear rating must be 200. That's the law, right guys? Right? (my wife is listening, speak up) See honey, I have to buy those Star Specs...
Yes! Yes! That is common in many states. Star Specs are nearly immune from the issue you are experiencing.
Very true about all four but I think you really want RE-71s instead of star specs. 
oldsaw
UltimaDork
8/13/15 10:34 a.m.
