I have a 1 speed SL, although I sometimes use a 177% ratio 3 speed and occasionally add a 38 T chainring so I am coming from the other end of the Brompton spectrum, so to speak. However, with your roadie background you may enjoy higher gear inches and you will need the wide ratio3 speed used in the 6 speed to get much above 84 or so. I do wish I had sprung for the TI fork and rear triangle since i plan to ride this bike for a while and it would be nice.p