I have a dimension on a shaft and it has two positive tolerances...this confuses me because if the two tolerances go positive that means that the nominal dimension is out of tolerance so why is it even the nominal dimension in the first place?! 

The shaft has bearings being fitted onto it so I see that the two positive tolerance phenomena has something to do with making sure that the bearings have a press fit which is desired in almost every situation where you are mounting a bearing to a shaft.. but I digress.

My issue is that I am having trouble figuring out how to tolerance a double positive tolerance without having to manually override the value...

Looking forward to hearing back form ya'll on the solidworks sphere.

Thanks

KP