Wheelbuilding spoke tension vs lateral truing

Question

I am using rim that is not bent, i screw each spoke nipples at equal distance from point when spoke thread is covered by nipple until spokes are tense.

i get perfectly laterally true wheel, however tension on some spokes comes out different than others some are around 30 kgf (300 N) more.

Why this happens?

When i start to set similar tension for each spoke rim goes out of lateral true and then i spend hours trying to true it while keeping every spoke tension equal which never works out because there's still individual spokes that that needs to be ~20 kgf (200 N) more tense than others in order to have rim laterally true, what's wrong here?

P.S. I am not worried about radial truing because rim is double wall it never gets bent radially.

Answer 1

The rim is probably not made by the very best of rim manufacturers.

I have found that I can create a radially and laterally true wheel where the variation of spoke tensions is around 150-200 N. I use DT Swiss TK 540 rims. DT Swiss is a well-known reputable rim manufacturer and makes high quality rims.

I suspect your rim has not been built to such a high precision.

I think 300 N variation might still be barely acceptable for low-weight riders not riding hard on narrow high pressure tires, especially if you tension the spokes such that the average spoke tension is according to the manufacturer's spec and not such that the maximum spoke tension is according to the manufacturer's spec. Also spoke count helps -- anything below 36, and low tension variation becomes more critical.

For me, I weigh over 100 kg and ride hard on narrow high pressure tires. 300 N variation in spoke tensions would be way too much for me because the loosest spoke would repeatedly go slack and the nipple would self-unscrew, destroying the wheelbuild.