When are we ever gonna get past this kind of lame advice. If a chain is replaced before it gets too worn the cassette will last thru many chains.Anyone replacing a chain ought to know how to measure one for wear too. All it takes is a ruler and the ability to measure a 1/16" elongation in a foot of chain tensioned. That much elongation is when it's time for a change and won't trash the casette. 1/8" will usually trash a casette. Pretty simple concept. Try and remember it.