We've had some fun learning that not all dips and bumps are visible. Two times we've tested our Road Kings on the IFS, with one time just tapping the bottoming out of the shocks against the stops...
I've had no problem driving many times 15-20KM below the posted speed limits. I make it a point to watch for traffic from behind, and I pro-actively look for safe passing areas and put my indicator on and slow down to let whomever is behind us by. If a trash stop, or the spread out rest stops available, I pull off to give them clear passage.
Not in a race, enjoy the slower pace, and it allows more time to slow down and stop to enjoy/avoid the animals.
Tire marks, scratches in pavement, wheel hubs, rear axles, and brown streaks from the passenger side of the road - are all indications to SLOW DOWN AND PREPARE:)!
Drive safe, have fun,
Smitty