HED Belgium clincher nipple and spoke recommendation

landdnl

I'm having a wheelset made up. Priorities are reliability, lightness and to minimize crosswinds. I'm fixed on using clinchers. For the front: Tune Mig 70(24 hole), Sapim superspokes, Hed Belgium 2 rim. As far as nipples go, I'm thinking the Sapim alloy locking nipples since the superspokes are a little flexy and I don't want the nipples to loosen if I hit a pothole. I'm not going to be riding this in the rain, so the alloy nipples should be fine. I just calculated spoke length of 278.3. So for the superspokes, would I need to go down to 278 due to the flexy nature of the spoke? Sapim recommends to go down 1mm from calculated length.

ugo.santalucia

I don't think you can match the superspoke with a nipple treated with threadlock compound. Maybe some who use them can confirm. I use DT and you can't match DT revolution with DT pro lock nipples... I would expect things to be the same at Sapim...
The spoke will wind up due to the friction.
Have you used similar spook before? They are not straightforward to use and avoid use them at the rear

cycleclinic

Super spokes are so thin and flexible I would not use them for a low spoke count wheel period. Lasers arer a better prospect but Race would be better on the rear. Laser spokes I find are fine on higher spoke count wheels .

Use Sapim nipple freeze instead of locking nipples it will do the same job. The locking nipple is likey to create more severe wind up issues.

As for length round down the next available length.