When dishing a rear wheel, is the goal to center the rim:
a over the hub
b over the hub+spacers+lockrings
c in the frame
Strikes me that b and c are the same.
I ask this because I converted an old ten speed to fixed gear. The BB spindle was pretty long and so it put the chain ring pretty far out. That forced me to put the cog as far out as possible, which forced me to put all the spacers on the other (non-drive) side. To do all this, I not only had to undish the wheel from the way it was stock, but now am wondering if I need to put some reverse-dish into it (you know, dish it towards the non-drive side).
And, I take it that the whole point of this exercise is to get the rim in the center of the axle to reduce the chance of bending the axle.