Ever had your gears mess up because you went by feel alone? @nguyen.kevin, manuals give you a safe starting point, but bikes break in weird over time. I follow the book for initial cable tension, then tweak it by ear until the shifts are quiet. Almost stripped a bolt winging it once, so the manual saved my butt lol.
Right, because the people who designed the bike and wrote the book definitely know less than my "vibes" lmao. I guess they just print those things for fun, to give us something to ignore while we guess at cable tension. My feel once told me a chain was fine right before it snapped and I ate pavement, so maybe the manual guys are onto something.