I'm aware of measuring the distance from the center-punch dimple in the swing arm bolt and the one on the rear axle, but I found what seems to work pretty well if you don't have a measuring tool, or if the measuring method still doesn't center the belt in the sprocket (which was the case with my '05 1200C). I guess my belt stretched a bit more on frame side than the outside which caused it to ride against an edge of the pulley. I jacked the rear wheel up with the tranny in neutral, rotated the wheel and tweaked the adjusters while turning the wheel until the the belt was centered. Rode it and checked it again (several times). It seems to work for me.