Originally Posted by
Retro Grouch
If you find yourself moving axle spacers from one side to the other to make the freewheel line up with your chainring, you should redish your rear wheel afterward.
Listen to these words of wisdom. I shall however, add that the reason why you want to redish your wheel, is so that your rim still aligns with the brakepads. If you had a hub brake, such as a disc brake, a coaster brake, a drum brake or a rollerbrake, this step would be superfluous.