gearing the hub for the low, and fitting the chainring size needed to one of these cranks ,
http://www.schlumpf.ch/hp/sd/sd_engl.htm
makes a chainring 1.6x larger via a planetary over drive gear ..
crank arms will then turn slower than the chainring..

R'off 38/16 top gear 91.93" becomes 151.68" with the Schlumpf Speed drive overdrive Crank.. can you imagine spinning that one out..

NB you still have air resistance to overcome ..