Hi,
I build a rear wheel last March with Formula fixed-free, CXP21 Mavic, ACI double butted black spokes. After couple of months, has started breaking the spokes on the nipple side. I have asked before in the forum and the problem looked like under-tensioned spokes. I tensioned them more but today another one broke when I put lots of power to accelerate and hit some bumps at the same time.

I think that since they have been under-tensioned for few months they have been stressed in the nipple side so even if have tensioned them correctly last time they tend to break easily now.

I am thinking to replace the spokes with DT or Sapim double butted, or what else…?

What do you think?

when i had wheels built for me in the past i always went for the toughest / strongest spokes possible
you are going to get massive forces going through them when you hit pot holes / bumps so i would go for the sapim double butted i have had these on three bikes now with no breaks ( apart from during polo but that was a ball travelling at some speed smashing throgh the rear wheel bound to break something )
what spoke pattern did you have some ( especially radial ) can be a bit weak 3 cross is the toughest i think, that or crows foot pattern

I did it 3 cross...thats why I am a bit surprised with the result...???

sorry my punctuation is non existant

3 cross and crows foot patterns are strong builds