I'm sure I could get by practically, with a 1x system comprised of a 39T front and an 11-28T rear. For the flats. And general boring commuting. I have improved my cadencing and can spin faster for longer and happily enough. Any time that road aims even slightly downhill, it's to the big ring we go. And on decent downhills and sprints, I'm either in or knocking on the door of that 11T rear cog. 13T max cogs are not enough by a long shot, per my riding environment and speed proclivities.