Hi guys,
A little background first:
I've just finished trueing/tensioning a wheel consisting of a 28H rim laced 3X to a 36H, high flange hub. (Why? well, using the bits I had it was the easiest way to achieve the configuration I wanted.)
This combo obviously required several different spoke lengths, so I did a drawing that described where the spokes would have been in a 28H hub and where they would end up using the closest available holes in the 36H hub. Based on this I was then able to come up with a pretty decent guesstimate for what correction factor to add/subtract to the normal spoke length for a 28H hub depending on the spoke's position in the pattern.
Anyhow, the wheel went together surprisingly easy, and only a few spokes had to be replaced with other lengths. I've gotten it true and round to within 1 mm, and spoke tension(measured) is also quite even throughout.
As a final step before applying the rim tape I measured how much each spoke penetrated into its nipple, and here's where it gets a tad confusing.
Regardless the mismatch hub/rim, I'm still using repeating patterns, left side mirrors the right side, when viewed axially the left half of the wheel mirrors the right half, spoke lengths are corrected the same way depending on their position in the pattern.
Yet when I find a spoke with low penetration in one place in the pattern, the next spoke in a corresponding position migh very well have a perfect amount of penetration ASO.
Why is this, what feature of wheel geometry is it that I'm missing?