My 18 Ultra has always had a shake when slowing down between 30-40 miles an hour. At a service at the dealer I told them about it and was given two answers; the first was they all do it and the second was tire pressure could be low but was only about two pounds off of spec in the book. I rented a 17 in Nashville and besides being ridden hard it didn’t do this. Anyone else have this come up? Mostly my other bikes this would happen on bad tires or fork adjustment and dealer saw none of this

This is normal. When slowing down, as the bike passes thru 35 mph or thereabouts. If you take hands off the bars at this time you may get a wobble. But it won’t wobble at steady speed on the highway if you take hands off.

This is is an old, old story. Don’t take hands off the bars as you slow down thru 35 mph.

My 18 SGS started this at about 14k. Rebalanced front wheel after checking air pressure, no change. I adjusted the neck bearings and that was the cure. 2014 and up are a different process than the fall away method used before, but the new method I’s in the service manual. Pretty good sign of the neck bearings is if it’s only happening on decel. Good luck.