As promised, I'm posting several photos to the Ax which has just over 12.5K miles wear. A close inspection reveals the fine line of different rubber compounds which make up the thread/tread face. Approximately 2-5/8" of the center is hard compound and the sides have softer compound. Ran my finger tip laterally across the thread face and I can actually feel the edges of the different compounds.
Wish I could enlarge the photos for better clarity! Maybe one of our Moderators can perform that trick
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