No need to add a spacer; the white-colored plastic male nut cover (wish I knew what it is called - I cannot find it in the parts fiche) can slide on it's axle. If you move it too close to the engine it will back itself off. It moves easily on it's axle.
Keep in mind I'm talking about a fifth gen.
I understand that bit, what I was refering to was the path of the chain would be 1mm closer to the engine as it makes its way around the front sprocket.
BTW, Partszilla calls that part a Speedometer Joint.
..blackdot/Tom