I experienced something the other day that really surprised me. I have been thinking my helmet (HJC cl-14 size M) I purchased when I got my first bike 6 years ago, was the right size. It is what I used last year at Sturgis to testride the convertible. Wind buffeting was the major hindrance to the bike of course. I thought then I could purchase a fb windshield and the problem could be resolved. Have not gotten to the replacement yet but last weekend I bought a new Shoei RF-1100 helmet size M that fits like a corinthian leather glove. no kidding. May just be the best helmet I have ever used. Almost purchased a L until going back again and resizing. Walked around in the shop for 20 minutes with the M and it seemed just right. So, on the last couple rides I have been on, the buffeting appears to be nill or at least very minimal. I'm talking about that feeling that the wind is blowing your head to the right and then blowing it to the left, and all over the place. I am beginning to believe the majority of my issues with the buffeting has actually been an ill-fitting helmet (sized just a skosh too big; like when you are in between sizes??) Anyway, my gf has been using a half helmet and the wind that day she said felt like it was going to take her head off......and she was riding behind me! Anyway, she is pleased so far with her new same model helmet as well. Not saying that the helmet fit is the answer but appears to have made a significant impact on the buffeting. It seems to be more one with my head. May be something to think about and try.