2022 SGS Special, under warranty, took in to the dealer in early spring because of this noise that comes from the left side rear axle. When the noise first appeared I though it had something to do with a warped rotor as the sound is not constant but rather oscillates. I put it on the lift then lifted the rear wheel, took a Harbor Freight stethoscope, not a rotor but generates from the left side axle/bearing/swing arm area.

Dealer said when they diagnosed it they couldn't find anything, taking rear wheel off and reinstalling. I'm making an appointment to have it checked again. Sometimes it's so loud you can hear it over the sound of the engine. In the audio link below, it's near the end, after motor cuts off. An oscillating whine.

15 second mark or about it appears the first time, then around 26-30, most prominent around 40

 

Yep, sounds like a wheel bearing. How many miles on the bike? On Harleys, I change the wheel bearings with every tire change. I don't like their factory bearings.

 

3,600