I just received my XL-FD hub that i'm using for this 650B wheelset.
Compared to the X-FD (which I have on a different wheelset) the XL-FD is Enormous! The flange diameter has gotta be over 4 inches!
beautifully made alloy hub shell as well. Its a real nice unit to hold. Quite a bit nicer than my X-FD just in terms of perceived quality while holding it in my hand.





If this doesn't stop ya, nothing will.