Originally Posted by
cpach
It's weird they have you specify the spoke lengths. I would have rebuilt that wheel with longer spokes if I built it for a customer (after some harsh words and a snack). While it's likely to be fine, it is a legitimate durability concern if the spoke doesn't thread past the edge of the rim bed.
There are no problems if the butted section is a different length, or indeed a completely different butting profile, so I wouldn't worry about that.
I called the shop and they said it was safe and that it won't break, although they admit that it is short.
They said they did calculate the spoke lengths themselves but didn't explain why they're all a little bit short.
I assume that they must have used the old ERD that doesn't match the shallower profile of the new batch. Or they simply used my calculations.
But they explained that for the NDS spokes with the elbow going out of the flange causes the linear distance to be longer resulting in the shorter thread engagement compared to the spokes coming from the inside of the flange. 2mm is a significant difference though.
Although on the old wheel that I built myself with a similar hub with same dimensions and the same model of rim (but with 36 spokes instead of 32), both the inside and outside spokes have the same thread engagement, but I did a lot of stress relieving with the rubberized handle of a hammer and pressed the elbow to get it flat and flush against the hub flange. I wonder if they didn't stress relieve at the crossing of the spokes in contact.
I would use the new wheel as it is, as I can only take one of them with me on the long tour (the old or new one), but I will still occasionally feel a bit uncomfortable wondering about the non-optimal spoke lengths ending at the bottom of the nipple heads..
I recommended to them to add an option to specify no length when adding the spokes to the cart on the website when someone orders wheelbuilding service.