I think you can only use them with a Maillard hub because of how they fit
not sure though. Try sending stidds a pm, even though he's Welsh he knows his stuff when it comes to this type of stuff ![daumenhoch :daumenhoch:](http://www.radbmx.co.uk/forum/Smileys/smilies/daumenhoch.gif)
Welsh, cheeky fooker.
![LolLolLolLol :LolLolLolLol:](http://www.radbmx.co.uk/forum/Smileys/smilies/LolLolLolLol.gif)
They are relatively rare hubs, the helicomatic freewheel can (as Ash says) only be used with Helicomatic hubs due to the fact they do not have a thread on the hub/freewheel, they have a twisted spline setup.
Very nice hubs and freewheels though, they were standard on Yamaha's (and I have them on my Yamaha) and some Peugeot's BITD.