700mm - Overlap
will get me to the nipple rim interface, but not the ERD as measured in
Spocalc (to the top of the nipple).
My eyeball measurement using a ruler is 3mm per nipple head or
706mm - Overlap = ERD
Would somebody please verify that this is right, or correct me if I'm wrong.
Thanks!
In my experience adding 3mm TOTAL (to the diameter, not each radius)
is about right, depending on the spoke nipple. I've successfully used
3mm for Wheelsmith, DT and "no name" nipples. Hi-E require a little
more fudging. :-)
Fairly clear directions are here for measuring ERD:
http://www.sheldonbrown.com/rinard/spocalc.htm#MeasureHubAndRim