Rant: guy at the shop in Portland saw my chain checker and asked why not just eyeball it
I was doing a tune up on a Trek Domane last Tuesday when the owner of the shop next door wandered over and asked why I bother with a chain checker when you can just look at the chainring teeth. I tried to explain that a worn chain stretches past .5 percent around the 2000 mile mark and eats cassettes, but he just shrugged and walked off. Am I crazy for thinking this is basic stuff, or do you all run into guys who still do it by feel?
My buddy let his chain go for two years because his rings looked fine, then had to replace the whole drivetrain at once. Cost him way more than a ten dollar tool would have.