Engine noise between 45 and 55 MPH

I purchased a 98 Valkyrie in October and love the ride.  There was a very high whine between 45 and 55 MPH when my wife and I took it out for a test ride. I asked the owner about it, he said all Valks have that noise.  Since then i have talked to two other Valkyrie owners that do not have that problem.  Does anyone know what the answer is?  It is not a subtle noise,  it is LOUD.

[Valker]

http://www.rattlebars.com/valkfaq/#NOISE
http://www.rattlebars.com/valkfaq/buzzbolt.html

I ignored the noise for several thousand miles on mine (I always ride faster than that , so I only heard it occasionally) and it finally went away. That was about 70,000 miles ago. The link talks about how to fix it.

Thanks for your info.  I forgot to mention that the bike has 10,900 miles on it and 10,200 when purchased in the middle of October.  We've had it up to 80 mph and the sound is not there and it goes away when the clutch is pulled in.

Jim