+1
I use a straight edge (actually, my 4' level) placed against the outside sidewall on the right side of the rear tire,front and rear, as close to the axle as possible, and sight it up with the chain. This won't change whether the bike is straight , leaning, sideways, or upside down. This after the chain tension & tire alignment is closely set by feel/eye.
I don't clean the chain, just add motocross lube once or twice a year. (and I use the "creeper" method for that.)(Creeping down the drive, one foot at a time
)
