When you adjusted your brakes, did you check to see if (due to pad wear) they were lapping over the rim bead. Easy check: Is there a "ridge" of pad at the top edge of the brake pad, or is it perfectly flat?
If it's got that ridge, then the sidewall damage at the bead is from the pad edge slicing the sidewall.
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"I feel like my world was classier before I found cyclocross."
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