for reference sake i measured my drum hub (b110).
Came up with these figures:
47mm from base to mounting face
82mm overall length
~155mm mounting face dia

If someone could measure up a disk hub that would be a big help in the unraveling of this mystery.

Piccy




Also i have been told the drum stub axle is thicker which means the bearing will have a larger internal dia. Im thinking if the disk bearing has the same outside dia as drum bearing then you could use the drum hub on disk bearing on disk strut and not have to machine outer dia of hub.
Could be a lot cheaper than a new hub??
Just putting thoughts out there
Hope you dont get annoyed with the info being in this thread. will move if you want.