Ah, that's interesting. Too late for me as I've already ordered the SRF3 though. I thought the sturmey archers took a splined cog (those notch ones) not a threaded one though - is the fixed hub different?
The S3X takes Shimano HG pattern cassette sprockets, but the major diameter of the HG spline is 1.37" and Sturmey cut a thread on it to take a single freewheel
Ah, that's interesting. Too late for me as I've already ordered the SRF3 though. I thought the sturmey archers took a splined cog (those notch ones) not a threaded one though - is the fixed hub different?