So I neutered my Dahon Helios P8 and made it a singlespeed. Chain ring is a Truvativ 52t. Zefal toe cups work very well.
Surly Singleator set in default push down position. Yes I know that push up will produce better chain wrap.
View of chain line.
I narrowed the handlebars as I felt too much wind resistance with the original size. I can also tuck my elbows into an aero position, hunch down and crank it.