S-A S-RF5(N) would build up as a single lever 5 speed .. and a 2 lever 10 speed ,

since it uses the 9 spline driver of the BWR hub they make for Brompton.





I went with a Schlumpf Swiss Mountain drive Crank, it's 2 speeds are widely spaced so the 3 hub gears are used twice.. 6 speeds.


If you want the conversion parts in the US talk to the dealer ..