-
is it any shimano hub disc that can be converted or just specific ones?
The Fixxer or Walker Brothers' copy fits any actual Shimano hubs from about 6400 generation up to 6700 generation, apart from most DuraAce and some cheap hubs you'd never see in the aftermarket. If it doesn't have an M10 axle, it probably won't work, so the new generation wheels (6800, WH-RS81 etc) are out. If the freehub isn't actually made by Shimano, it won't work either, the method of taking drive from the rotor to the hub shell will be wrong.
is it any shimano hub disc that can be converted or just specific ones?