I have a 2009 ultraclassic. When slowing from 40 mpg down until about 30 mph it shakes. It feels as though it is coming from the rear. I have had the back tire replaced twice as the dealer told me that was the problem.

Check your rear wheel is balanced. Also check that the alignment is good, straight check visually that the wheel is pointing straight. Check your rear shocks are OK they can go blow seals. Check air pressure level. Check your rear brake pads are OK and caliper is working properly. Check your belt and rear sprocket for wear.

You might need a swing arm kit. I replaced my outside bushings and it points great now but my bike is a 1990 FLTCU , yours is pretty new.