How tightly do you tighten your cassette lock ring?
The torque spec for cassettes is around 30 ft/lbs. That's quite a bit, way more than I would use if left to my own judgement. Using lots of torque snugs the cogs together so they spread the force acting against the freehub body rather than each cog individually.
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My greatest fear is all of my kids standing around my coffin and talking about "how sensible" dad was.