Buy the 6 speed it is usable for most rides. To bad brompton has not made the drop outs wider and offered a Nexus-8 or Sram-9. It realy could use a wider gear range and would be less complicated then the current 3 speed + rear derailer. Also more gear range with out a front drailer or Mountain drive. I have a rear rack on mine. Have never used it. Seems to be more stable when flolded and parked and may roll easier. But it could just be the inline skate wheels I added.