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Well I kind of measured it the way the link said. I didn't measure to the screw flat, I measured to the top of the rivet in the rim. I remeasured the way it said and I got .5 difference. now I'm at 538mm ERD still 1mm smaller then the web site and 2mm smaller then what the sticker on the wheel says.
What ERD represents in the spoke calculation is the circle made by the ends of the spokes, so you want to measure it to the point where you want your spokes to end up. :thumbsup:
There is some lingering confusion about how to measure ERD, but if you study and understand the spoke calculation, particularly a diagram, it makes perfect sense.
I used to have the spoke length calculation in my gallery, but it looks like it got wiped or something... we had today off and it's on my work computer. I'll post it monday if i remember.
I did pick up spokes that are 258mm and 260mm and measured them. I find it odd that the 258mm spokes measured 257mm and the 260mm spokes measured 259. Is that some what normal? If that is the case I think the shop might have used 261mm and 262mm spokes when the wheel was built. Basically making the spokes 2 mm too long.

I thought getting the 258mm and 260mm would only be 1mm difference but it looks like it will be 2mm. I think I will go with the 258 and 260 (measured 257 and 259) That is 2 mm shorter then the original spokes (going more by measured size rather then box size) it was built with and should eliminate the bottomed out nipples and still be in the sweet spot of the nipples.

I would post a screen shot of the calc but I don't have enough posts yet.
here are the measurements I got from the hub and rim if you want to know.

ERD 538
hub center to right flange center 20.9
hub center to left flange center 33.9
Flange dia L+R 57.4
DT 12mm alu nipples
3 cross
32 hole
I'm betting you'll be good with the new spokes. :)
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