Just noticed that while riding between 55-65 MPH, the bike has sort of a wobble when I let go of the gas.
I did a bit of research on the web, and they say it could be the steering head bolt is loose?
Any suggestions? Driving me crazy!

 

You'd be best to just search the forum.
There are hundreds of threads related to different causes of the "wobble".

I don't believe there is one that is more prevalent than the other.
The cause of my "wobble" was an out balance front tire.

 

 

My 16 Deluxe had a bent rear wheel which caused a wobble/hop, if you can put it on a cycle jack to check the lateral runout on your rims, check spokes and tire condition, do a fall away check that will let you know if you have to adjust the head/neck bearings. Ride safe, Good luck.

 

Check fallaway. But I bet it is the tires. Those needle bearings in the steering head will last a lifetime if they were right a while back and you do not use your Harley for ramp jumping.

 

 

Spokes are easily, and commonly, overlooked.

 

Found the culprit...loose rear spokes. My local mechanic carefully tightened each one, now rides straight as an arrow! I was happy he did not have to take off the wheel or tire off.