Originally Posted by
fietsbob
S3X Threads the tips of their splines , making a screw on Freewheel a practicality, if you get tired of your feet being pushed around going down hills..
You can also thread a standard track cog and BB lockring onto the S3X, and if you use one of the splined spacers provided with the hub between the cog and the lockring, there's no risk of it being a "suicide hub."