....Do you know the spoke tension these can hold, or is it just "yeah quite good, a lot of spoke tension"?
FWIW, I asked a professional wheelbuilder who uses open mold rims, he said something like "I use a max tension of 130kgf on our rims (this leaves significant margin for error if someone steps on your wheel or some other random incident)."
this is an important data, cause it will tell you if you can go for 20-24 or 24-28 spokes. That number is not too high, so yes, it leaves a margin for "incidents", but it's not tensed enough. 150-160 would be a better mark (not for the spoke tension, but as the maximum load a decent rim should resist). Thing is that you can´t make magic, it will be either too heavy compared to alu or too weak for less spokes. 382g for a 38 carbon clincher it's very on the weak side I think. But if you leave the spokes with low tension or you just don't brake like pefendreu, there will be no issues, but it won't be stiff enough and not braking it's a extreme sport. I've seen deformed carbon clincher flanges from any brand, you name it; reynolds, enve, shimano, campagnolo, asian rims... I don't think these rims are better than enve. But I may be wrong of course.
If I'm not mistaken, I am the wheelbuilder in question here.
It's important to note that I was speaking about the rims that we use, which are not FarSports rims
. Though they look roughly similar, my experience with the rims that we use should not be considered applicable to any other rims (as I explained when I was asked originally). Only the people who made your rims can tell you for sure what tension limits to use. Therefore, my statement can not be considered "important data" as regards this discussion.
There is absolutely no use in the world for putting 150-160kgf on spokes. You are approaching (or exceeding) the ultimate strength of a lot of spokes at this tension, you run a high risk of deforming or breaking hub flanges, normal spoke wrenches are useless at this kind of tension - you would need to use hex drive from the inside, and most importantly you are doing all of this for zero benefit.
The rims we use have been tested with excessive spoke tension. Spokes break before the rims do. The absolute limit of what the rim could take is well in excess of your 150-160 number. The safety margin I reference is far bigger than what you are assuming.
Zipp has a maximum spoke tension on their rims of 100kgf. I think if 130 being under tensioned had any validity at all, then you would just see massive epidemic failures of their wheels, which you simply do not.
Beyond the point where the spokes are prevented from going slack, increased spoke tension has no benefit in increased wheel stiffness. This has been tested and documented many times. http://www.sheldonbrown.com/rinard/wheel/index.htm
Our forthcoming new rims, which are being produced by the same rim maker as the open molds we have used but are not open mold rims (we own the mold), are designed to be built with the same 130kgf max as we have successfully been building with for several years and many many many hundreds of rims.