So i'm change out the back rim of my 2006 softail stander FXSTI. from stock rim to Spoke Mammoth Rear 18 X 5.5". the problem i'm having is the spacers, the axle will not go all the way in to the belt adjuster on the pulley side. Does anyone know where i can get spacers to fit or how much i will need to cut off?

 

You about measuring the stock rim with spacer and compare it to new one with spares.
That should give you the difference.
Just thinking