Re: Cranbrook, Chain shake/flap/slap
I would use the tightness of the rag jouint bolts to align the sprocket as carefully side-to-side as you can. I have had more problems with the sprocket being off-center, which causes the chain to tighten/loosen/tighten/loosen, and that causes a lot of noise and some vibration. I did run one bike like that for a loooong time with no ill effects, but it's better to get them as close to perfect as possible without tearing your hair out.
I tighten them about 3/4 of the way, then use a rubber mallet to get it close to centered, then carefully tighten the nuts, keeping the sprocket strait. You don't need to make the rag joint bolts super tight, just snug.