guess the next test is to get those OEM tires off of there, maybe replace with American Elites and see what changes eh?

 

Its simply a function of the geometry of these bikes. Its what happens when you take your hands off the bars while slowing down. They arent designed for taking your hands off, and Harley will never take responsibility (nor should they) for what happens when you take your hands off the bars. I would of course check to see if anything else is in need of repair or out of spec but my advice: don't take your hands off the bars. There are tons of threads on this over the years...

Other than that, GRBrown will be showing up soon to set us all straight.

 

My 17 Limited did the same thing starting around the same mileage. Ignored it for another 3K miles then had to replace my tires due to wear. Put on American Elites and the problem is totally gone now.

 

With 15k on tires, probably your problem . These tires wear a flat in the center but it varies like a bunch of S waves up the side wall. When you go into turns, as you roll over these areas, you have wiggle or weave depending on tire. Jack bike up. Nail a piece of 120 carbide paper to a board. Carefully with tire spinning, roll around tire tread. You will see if that is what it is. Any low spots on side wall is steering bike.
My soft 540 rear gets so bad, by 10k, I just replace it. Like night and day difference. After 3 lops, switch to Mitchellin. Now I ride so little, not sure if I will ever know it will make a difference.

 

 

For the rear, you could always cut the cupping off. Takes minutes using one of these (wood rasp):

 

This is why there are 1,000's of posts on tires. Everyone has a preference and yes it sucks they have to be changed. EXPENSIVE! There are many great brands that are better than the OEM tire. I am not emotional about it. The only reason I went with American Elite is I used them on a previous bike and was very happy with the improvement.

 

Loose neck bearings was the problem on my 08 Fatboy. Tightened the bearings slightly and bike was smooth as silk hands on or off. Had a noticeable shake before.

 

Curdog is most likely right. Head bearing torque. I don't know what kind of set up the OP's bike has. But my 2018 RGU has a nifty adjustment mechanism that doesn't require much disassembly. Check your shop manual and see what the specific procedure is for your bike.

On my 2018 RGU, I had to remove the ignition lock and some plastic below it to reveal the neck clamp. Bike with front wheel off the ground. Loosen the clamp, then use a six inch long 1/4" socket extension. Poke it up from below. Counterclockwise tightens, clockwise loosens. It doesn't take much movement to make a big difference.

The book describes a method to calibrate the front end "swing back" but this requires the bike to be absolutely level front-to-rear and side-to-side, which is pretty difficult to achieve in my garage. So, I skipped the swing back measure, and merely adjusted the adjuster until the front end felt "right" to me. Then went for a test ride. Test ride revealed that I got it right on the first try.

My problem was that my front end was too tight when it was delivered to me. It was so tight that with front wheel off the floor the wheel would not return to center when deflected and released. This caused the bike to weave side to side when traveling in straight line at steady highway speeds. Once I loosened it up a bit, the weave went away. If you go too loose, you will tend to get wobbles in sweeper turns, and the slow down wobble will be worse.