The humming may be inherent to the Elite 3's. I know that when I put a set of radials on my Magna, they made a humming sound from 40-45mph. Any faster or slower than 40-45mph and there was no humming sound at all. Does the sound go away if you are higher than 55mph? You may want to seek out other Elite 3 owners and see if they experience the same thing. If that doesn't yield any results, I would either take it back to the dealer or trouble-shoot myself.