A bit about the bike: Custom rolling thunder hardtail frame with a 250 rear tire, driven by an open belt system and has an evo motor in it. I took it out this morning and while riding it felt a bit different. I noticed that my rear tire would start shifting, on the right side, back and forth. Checked it and the bolt is as tight as can be.

Not sure what the issue is here? Maybe the chain is too tight?

 

Rear wheel bearing.

 

Something looks amiss here, and I agree: bad wheel bearing.

 

Bobbed has at least three threads going on this topic. The problem may be a damaged/broken part that he has posted elsewhere.

 

the other part i listed as broke has nothing to do with why it's shifting. That piece is more like a shield from the adjustment screw.