SOLVED: Thanks everyone! I was worried that the saddle would fall apart with further riding in the rain. Glad to hear it won't and that it's merely minor cosmetic wear.
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I recently rode for 1 hour in heavy rain and my 4-year-old Brooks B67 suddenly got worn down to its white inner at the front.
I know rain isn't great for leather saddles, but I didn't expect it to be so extremely damaging. Perhaps it was due to my rain pants rubbing on a soaked-through saddle?
Is there a way to avoid this? I'm spending the year in rainy Patagonia. Do I need to switch saddles?
Thanks for the advice!