Now that is interesting. I have just made some anodised shims to make up a 3.0 mm gap between the bush facings and the frame adjuster bosses. The shims are both 1.5mm. But the swinging arm spindle is 0.5mm shorter than the swinging arm so I have assumed I will need to add shims to the spindle to make up 3.5mm plus a bit to allow the arm to move. Bearing in mind the bush facings have worn from new, I am not sure how the bikes left the factory when new. Mine must have needed shims or the spindle would never have moved in the bushes. Probably why my bushes are not worn even after 12000 miles.