I have a chain wear tool, I just never use it. Checking chain wear isn't something you should have to do every week or so and it isn't something that needs to be done super accurately either. A 12" metal ruler suits me fine.
If I decided to start using my chain checker again, the first thing that I would do would be to calibrate it against a brand new, never used chain.
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My greatest fear is all of my kids standing around my coffin and talking about "how sensible" dad was.