I hope this doesn't come across as anything but how its intended, to correct some misinformation I've seen posted.
Preload is used to get a specific sag setting. Whether one person, two, with luggage, soft ride, firm ride, etc. Sag is not a guessing game, it is a specific measurement then preload setting. Its not perfect but a compromise to get the bikes suspension to work for you and not against you. You could and should have different settings depending on passenger, luggage, highway, curves, etc. That's why a rear pre load adjuster is popular. Wife riding today? X number of turns, riding across the state with gear? X number of turns. Ready to ride the curves? X number of turns. Like changing belts, you need to check your sag on a regular basis. If anything is out, you'll know it.
If you can't get the proper sag, you need to find a suspension shop and get their help.
Again, I hope this is received as intended, helpful information. I'm not a suspension expert by any stretch of the imagination, but I do try to read up on anything that might make me a better rider.
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