I recently built up my first set of straightpull wheels, with I9 hubs and traditional DT Swiss Competition spokes. (Hubs were from a I9 Trail S Hydra wheelset and are very much like DTs.)
Something I didn't expect, but ran into, is that when finishing up tensioning the wheels, it seemed like the inner and outer spokes on each side required a slightly different tension; about 1 number on a Park TM-1 tension meter.
This seems to makes sense because the spoke holes for inner vs. outer are a few millimeters different when it comes to flange distance, and thus the inner (steeper bracing angle) spokes would likely have a slightly higher tension.
The wheels built up wonderfully and I had no problem getting to even tension, but it was a bit surprising at first because instead of having one final tension for each side of the wheel I had a (slightly) different for inner and outer spokes on each side of the wheel. For example, here's the numbers from the front wheel:
- NDS (L) Inner: 22 (117 kgf)
- NDS (L) Outer: 21 (105 kgf)
- DS (R) Inner: 20 (94 kgf)
- DS (R) Outer: 19 (85 kgf)
So my question: Is this normal?
Due to what's effectively a slightly different flange spacing it makes sense, but I wasn't able to find anything about it searching around online, so maybe it's just one of those things that's understood/accepted by more experienced wheelbuilders?
(If it's useful I have a full writeup on that build here.)