E-mail Kirk Pacenti. See what he recommends with regard to max DS tension and spoke gauge. It's very possible that he may recommend no higher than 110kgf and DB spokes on such a light rim.
In another forum someone asked Kirk and he said he thinks 110kgf is sufficient and that he recommends a max of 125kgf.
The context was not a discussion of clydesdales on his wheels, if that changes anything.
ps: I haven't had the money to order all my parts yet, so I've been piece-mealing it. I have the front hub, the rim tape, and I ordered the nipple washers. Haven't ordered the rims or the spokes yet.
edit: oops, someone posted this already. Shoulda read all the way to the bottom before quoting bigfred.
Last edited by SethAZ; 11-19-13 at 08:31 PM.
Reason: someone else already posted this
I just posted about finishing my first wheel build that I was talking about here, which used the SL-23 rim as the OP proposed, but dropping the CX-Rays in favor of double-butted Sapim Race spokes instead, on the advice of others. About to take it on its first long-range ride in a few minutes.
Interestingly, the Continental Grand Prix 4000s tire, in 25mm sizing, measures 28mm wide at 110 psi when mounted on the Pacenti SL-23 rim, which is 24mm. The GP4000s at 120psi mounted on my rear wheel, a Mavic CXP22, which is much narrower, measures 26mm wide. That rim width changes everything, and the new front wheel feels noticeably different on the road, at least just riding around the neighborhood. I'll have more of an impression about it after today's ride.
Forget the fancy CX Rays. Use standard 2.0/1.8/2.0 DB spokes with a reasonably durable rim and quality hubs and go 32/36 if you're over 250lbs.
I do this on 32 spokes and I'm lighter - On a good day, I'm not even a clyde.
DT spokes Competition; Ultegra hubs; Mavic CXP33 rims.
This combo just works for me - over time, over funky terrain, but not over my budget. I've reused the rims now as I replaced the hubs (and spokes).
Awesome to be able to customize your own wheels though, no doubt about that. enjoy it.