Originally Posted by
dsbrantjr
That bike appears to be a single-speed with nutted rear axle and horizontal dropouts, so the rear wheel alignment (and chain tension, which should be "no tension") will be partly determined by the installer. Perhaps you should look up some instructions or videos on how to do it properly, or ask at the shop. Again, the chain should never be tight, it should be able to move about a quarter-inch up and down.
Try this:
It's hard to tighten the drive side dropout because the axle wants to walk forward. Try tightening the nut on the left side of the axle first. Then you can hold the wheel midway between the dropouts while you tighten the drive side.
__________________
My greatest fear is all of my kids standing around my coffin and talking about "how sensible" dad was.