We might be getting some terms mixed up here. There's BSD - bead seat diameter. That's the ETRTO size you see in fine-print on the tyre. If you look at the Sutherland's manual in the wheel-building section, there's a correction for rim-depth of various models. These range from -3mm to -50mm or more depending upon how deep the rim is. Basically ETRTO minus rim-depth = ERD effective rim-diameter. That's the diameter where the nipple-heads would lay.
Originally Posted by BillP
Is there some sort of millling cutter or chuckable file that I can use, or maybe needlenose plier type cutters? I don't fancy taking the spokes out to trim them. Regards Bill P
Yes, it's called an end-mill.
What I want to know is how they managed to spin the nipples down far enough so that there's 5mm sticking out above? Most nipples would bottom out with 2mm sticking up.