Personally I think if it's more about you and whether you look cool then your a poser. If it's about the wind in your face and the love of machine your on whether it be Harley or a metric then your a rider. "Biker" at least to me becomes more complicated. Maybe it's the fact that I have been riding a hog since the 60's when Harley riders were on the whole segragated into two groups cops and bad guys. Or maybe I'm old and crotchety.
A "Biker" to me is someone who embraces the whole lifestyle which is a list to long and boring to get into here. Suffice it to say if you spent 25,000 to 150,000 on your ride and only drive it from the trailer to main street of what ever bike ralley your at and back the term "Biker" is not something that describes you. And in the end a few of these posts have it right "who really cares". In this day and age all things seem to have been blurred together anyway and so with the terms of the bygone days of the biker lingo. So if you spent the cash and enjoy your ride call yourself anything you like and if folks want to give you garbage about it tell them to (self edited saving a mod the trouble) off.