I am riding a SESG 2012 with only 3900 miles on original tires. I have a feeling it is the front wheel bearing. Do they use a needle bearings or a bushing type in the front hub? I have seen needle bearings that will make a vibration when under thrusting or lateral pressure make this type of noise when showing signs of wear. I purchased the bike with only 3100 miles on it about 4 weeks ago and listen to the stereo fairly loudly and there is some vibration I can feel in the handlebars and highway pegs from my music. At first t thought it was normal and from the music, last night turns off the music and it was still there. That is when I started to work on isolating the source. I have had problems with cupping on my old bike ( Yamaha Roadstar) even though I watched the tire pressure very carefully. I am a fairly heavy guy , 275 lbs, so I know that payload, and pressure are the keys to avoid cupping. When I would have cupping it was a lower freq. vibration than this is. Currently I have 3900 miles on it, so for all practical purposes it is just getting broken in.