Originally Posted by
Peterpan1
I was surprised when I emailed Velocity to find they build all their wheels to the same tension regardless of size or spoke count. The park converted numbers are about what CFboy mentioned, so his wheels are dead on. One of the advantages to building with quality stuff is one can get a manufacturer's recommendations for the the tension.
Here is an article that relates tension to musical pitch. While this might be more difficult than a gage, it might be fairly easy to establish on the run in SA, and also as a method of checking tension of adjacent spokes. It is possible to have fairly divergent tensions even when the wheel appears to be true.
Yes, my point in trying to help out the OP by checking tension by pitch and going off his front wheel.
I was also surprised to see the Velocity info back when I started building wheels. Spoke tension varies quite a bit as the wheel rolls. Suprisingly, the greatest spoke tension is in the spokes on either side of the contact patch, not on the top spokes. In any case, if all the spokes are to remain tight as the wheel rolls, even those at the contact patch, they have to be stretched during the initial build. So my guess is that Velocity figures their wheels will be built with 14-15 butted spokes and these tensions adequately stretch those spokes, so their rims are designed to support these tensions. Hence the number of spokes doesn't matter. They're not being tensioned to support a load, but rather to stretch the spokes.
The interesting thing about the Rolfs isn't the variation in spoke tension, it's the level of tension - very low compared with a traditional build. 140 lbs, which is only 64 kgf. So much for the talk of how all low spoke count wheels are in high tension and apt to fail! My guess is that either Rolf's spoke material stretches more easily than the usual round steel spoke and hence required less tension, or perhaps the stiffness of the rim allows much less change in spoke tension as the wheel rolls, hence less stretch is required. However that may be, the Rolfs require the least attention of all my wheelsets.
And in any case, stretch those spokes! That's what keeps them from breaking.
Oh . . . and this stretching business is the reason that wheels built with heavier spokes are not stronger than those built with normal spokes, which is an appropriate thing for a tourer to be aware of. Heavier or unbutted spokes at the rim's specified tension will have less stretch. 10 spokes at 110kgf = 1100 kg/wheel! Don't need more strength than that.