Originally Posted by
rpenmanparker
Works for rims fine, but I think you will just end up with a mess trying to do a hub that way. Two hubs connected to the same rim while the switch out is going on will just be getting in the way of each other. If the dimensions of the new hub allow it, you should have no trouble using the same rim, spokes, etc. But be sure the flange diameters and spacing are the same or you may need new spokes.
I've already checked the spokes and they are the same within .1mm. Almost every Shimano mtb hub made since the 90's has nearly the same dimensions, give or take the flange spacing for 9sp.
As for getting in the way of each other, that's what I'm thinking too, but maybe there'll be enough play. I'll give it a shot and if it works great, if not I'll have to keep track of the four sets of spokes.