I also use a 1X7, there's a photo on my sig. The chain-ring is lined up with the middle cog of the cassette. I use chain-ring spacers to achieve this instead of buying a new bottom bracket. The chain rarely falls off with the non ramped ring that I use now. However when I use Shimano rings that are ramped, the chain would fall on the outside just after up-shifts over multiple cogs in one go.