Motorcycle Repair: drive train noise, front wheel bearings, brake rotor

Question
I have put 1900.00 into a total rebuild on engine and tranny on my 81 ironhead..trying to fix this humming noise.noise gets louder as speed increses not in relation to rpm.s.
 this noise is not extemely loud but sure is irritating.noise gradualy  starts after 6 or 8 miles..help! possibly rear wheel bearing?...
maybe that plastic shoe in the primary?someone says may be a chain?rear brake rotor is slightly warped but..could that make a noise..any help or advise very much appreciated.

Answer
Trying to pinpoint noises on her is tough, due to the fact I cant hear them.
I would start by riding the bike down a smooth road. Run it up to around 50 MPH and pull the clutch in and shut the bike off so you coast. DO you still hear the sound? If you do try to pinpoint where its coming from. If its the rear then I would check the wheel bearings and chain. the chain should not be still or rusty. When rotating the wheel the chain should not kink. if any of the above then you need to replace it.
If its coming from the front then check the front wheel bearings.
Your shoe in the primary usually doesnt make any noise. Your rotor makes an rubbing noise when its overly warped.
Hope this helps
Mike