I suppose the engineer gene in me is what makes me change tires as you do Tom. I use visual inspections for daily judgement, looking for cuts early on, and later measure them when I service the wheel set. I can't ride a really worn tire to save me. they don't cost much and I really hate walking and/or carrying a bicycle.
Bill
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Semper Fi, USMC, 1975-1977
I Can Do All Things Through Him, Who Gives Me Strength. Philippians 4:13