I remember from the build that Gaspipe started, that he removed some material from the paralever shock mount, nut much but it gave him a little extra clearance.
I think he was using a Michelin Desert and it was close fit and grew at speed.
His thread
http://www.advrider.com/forums/showthread.php?t=69015
was this one. Towards the end it got hijacked and he stopped posting about it. That was a downer.
you will have to trawl through the thread for the bit about where he removed some material. my search skills are not that good, maybe MsLiz can help there - she is the queen of searches I heard.....
Also, from what MsLiz posted, that explains the other threaded holes in the drive hub, for the disk on other models.
Hay Ewe