The light truck in front of us had its spare tire mounted on its backside. The spare must never have been driven on, still had its sprue bristles. But wait a minute, it had them only for a 180-degree span on the bottom. None on the top.
I make this suggestion because on my car, which because of where I live, always has the driver's side door facing south, has all the rubberized trim on the left side of the car cracked, broken, and falling off, while the trim on the right is still new-looking.
UV brittling is definitely in play, but the tire just had such a sharp trimline at each side (well, as best I could see from behind it in stop-and-go traffic). The sun exposure would grade more evenly there I figure.
Precipitation, that would bring gravity in to explain the sharp top/bottom effect. But sprue-stripping precipitation? Freeze-thaw something something maybe?
How about this, the sprues *are* brittle all over the tire where sun reaches, it's just that it hailed this one time and and knocked off all the ones on the top, and nothing has knocked off the ones on the bottom yet.
no subject
Date: 2011-05-22 06:52 am (UTC)no subject
Date: 2011-05-22 06:54 am (UTC)no subject
Date: 2011-05-22 07:04 am (UTC)Precipitation, that would bring gravity in to explain the sharp top/bottom effect. But sprue-stripping precipitation? Freeze-thaw something something maybe?
How about this, the sprues *are* brittle all over the tire where sun reaches, it's just that it hailed this one time and and knocked off all the ones on the top, and nothing has knocked off the ones on the bottom yet.