Ok so everyone knows about fake YYRs however their is new standards that will determine the fake or the real, the fakes now have machining marks and make similar sounds when you scrape with your fingernail, the bearing seat is another thing you look out for, shallow bearing seats would mean its fake,fakes are getting harder and harder to tell from the real ones,the best way to tell is in person, IE go to contests, club, etc. and try them examine them for yourselves, if your not confident send them to a friend you trust,who you know has real ones and have he/she determine if its real or not.
Hope This Helps