Originally Posted by
FBinNY
The theoretical locknuts, or the faces of whatever bearing support system he uses. 100mm is the nominal width of the built hub to match a fork with 100mm dropout width (standard front fork). The built hub will be 100mm wide at the mounting face and 4mm of axle would potrude at each end for the fork to sit on.
Who cares?
The 100mm is superfluous. His QR axle is 108mm long, with no particurlary outstanding features such as shoulders. Hell you could specify any hub < 100mm in width and have more than enough left over to actually fit in the fork dropout.