So Softails's come from the factory with the lightest setting on the read shocks which is only good for solo riders weighing less than 180 lbs. If you weigh more yourself or you want to ride with a pack, a passenger or both - you need to adjust the preload on the rear shocks to safe your back, your passengers back and potentially your ride. A properly adjusted suspension makes all the difference!
Both the owners manual and service manual have a section describing the basics of adjusting the preload, but nothing from HD offers the actual steps to take or any guide to adjust for a specific weight. The procedure is very simple but without a guide you're left to trial and error and a lot of jacking or relying on a shop to make the adjustment for you. This is based on articles posted online by dealers and HD service shops (and doesn't that defeat the purpose of having an HD in the first place?).
This is not an exact adjustment, and perhaps that's why HD doesn't spell it out. B