Technical What’s causing “stringing” on my white wall tires

good questions.
Tire pressure is 32psi (per Coker's tech recommendation).
Size is 800R14 (original size), wheels are original for 1960 Ford Thunderbird.
The strings are rubber. I cut them apart and looks like it's all white, so it's coming from white wall. There were no strings when the tires were mounted. I took them to a discount tire per Coker's recommendation. The tire shop said they didn't see anything unusual on the tires.
The only cleaning solution I have used, is bleche-wite and water.

My guess is there's too much material on the tire that is now wearing off. I'll mark the tire/wheel with crayon to see if the tire is moving against the wheel. That was a good idea.

 

Every factory whitewall I have ever seen was molded into the tire when the tire was made. The same reason that with certain white letter tires you can cut/grind the sidwall to get a wide white.
That makes me wonder if Coker is applying the white wall after the tire comes out of the mold.

As far as the whitewall being fabric reinforced, Not on a factory whitewall tire, If you cut the sidewall out of an old bias whitewall you can easily see how they are/were made.