Mine is an R1250GS HP, about a month old, with 980 miles, just had first service. It sounds like a freight train whining from the forks, when going 40-65mph. Below or above that, it goes away. I changed the wind screen, which actually helped a bit, but not much. Was pondering changing tires also, but from the forum, that doesn’t sound like it helps much, if any. I have noticed when changing direction of travel, and with different cross winds, the noise is sometimes greater or worse, depending on the direction. On a ride yesterday, it drove me nuts, then I changed roads and it all went briefly away for a glorious 15 minutes! This makes me think it is a design issue relating to tires, forks, fender, perhaps even the drilled hole spacing in the disc brakes, or a combination of all of these. I almost returned the bike a week after I bought it - but everything else is so wonderful. I use “Radians” custom molded earplugs (do it yourself) get them on Amazon, they reduce sound by 30db and are cheap. You really should use ear protection! But sound is Still obnoxious, still not acceptable, but way better. Am very disappointed in BMW and their lack of attention to this issue. And yes, the writers doing the reviews are ignoring it as well - probably because they are getting freebie trips and use of bikes. Do you really think they would be invited back to Sardinia, Spain, or where ever if they wrote negative remarks? I know several others in the market looking to buy a new BMW, but they probably will not when I disclose this and have them ride mine.
PS, to everyone hearing engine noises, all I can say is mine is just great. And after the first oil change, I think it even runs better. I know, weird.