All above advice is good. Redishing is usually necessary to get good chainline. Remember that with SS you don't have the RD keeping the bottom chain run aligned with the cog for you, so the chainline has to be pretty good. The great and powerful Retem claims that 90% of bikes will work without redishing if you use the inner chainring position on the front and throw a BB lock ring then a BMX freewheel on the back so that the lockring acts as a spacer moving the freewheel out, it's gnarly but it probably does work.