Felt like a flat rear tire. I stopped and both tires had correct pressure. Checked belt, seemed correct. Start off slowly, as soon as I accelerated the back end is unstable.
Parked the bike and got my trailer to get it home. Belt is now loose. Front and rear engine mounts look okay. Axle bolt, brake disk bolts, everything in back is tight.
I am thinking there is a front pulley issue or driveshaft.
Any ideas? Taking it to the shop Tuesday.

 

Need a better description of what’s happening. Is it wobbling? Is it surging?
Clutch slipping? Wheel bearings shot?

 

Wheel Bearings or Swing Arm Bushings

 

I'd go with wheel bearing also. Axle over tightened at last tire change maybe.

 

Left rear wheel bearing toast, right side was close to failing. Pick it up today.