Originally Posted by
FlashBazbo
I've been riding for decades and I ride between 7500 and 8000 miles per year -- now, on 11 speed. I have NEVER replaced a chain because of chain wear. (I have replaced the chain when replacing a worn out chainring set or cassette. Just never for the sake of chain wear.)
I'm not an expert but I would assume the worn out cassettes were caused by worn (stretched) chains