Originally Posted by
davidad
Low spoke tension can be the problem. I built up a rear for a 225lb.er with his Powertap hub. That hub has a little more dish than normal so that the nondrive tension was low. He was breaking nipples on the nondrive side. I added another 20kg of tension to the drive side so that I could add some to the NDS and he no longer had the problem.
Did you see how deeply the spokes ended up in the nipples? Low spoke-tension may be the final-straw that did in the nipples used with too-short of spokes, but it's not the actual cause of the problem. Regardless of tension, any time you break a nipple, it's pretty much a sign of too-short spokes. Although I have seen some cheapo nipples with super-thin heads, about 1/2 of normal, and those snapped off the edges of the head in a clean ring.