Bicycle Mechanics - Non drive side spokes breaking

Yet another spoke thread. I did a search, but didnt find one that was exactly like mine. I am 5'10" and 140 - 150 lb. The wheels have 5000 miles on them.

I have a set of custom wheels with DT rev non drive side spokes laced 2x 28 hole with aluminum nipples. They were perfect for the first 5000 miles (1 minor true needed). 3 weeks ago, I broke a non drive side spoke at the cross point. The same thing happened on Friday.

Both breaks occured when I was standing going slowly up a hill, like when starting a ride and you have a hill, but are not warmed up yet. - so a decent amount of torque.

After the first break, I had my shop (a very good builder) replace the broken spoke and retension the whole wheel.

I am going to try and replace the broken spoke 1 more time, and see how the wheel holds up. If not, I will probably rebuild the whole non-drive side.

Does anyone have any ideas why this may be happening? Or perhaps other questions I should be asking myself about the cause?

The only thing that I can see is that there is obviously some scuffing of the spoke (black) where they cross, and this appears to be stressing them to failure.

Usually, non-drive spoke breaks indicate the tension is too low. The tension has to be really high on most wheels. I was breaking spokes and I had to crank the spokes to the point that the square on a couple of nipples just started to round off before the problem went away.

If I jack up the tension on the NDS, then wont it pull the rim off center?

If I jack up the tension on the NDS, then wont it pull the rim off center?

You have to increase the tension on all the spokes, otherwise, yes, the dish will change.

The wheels have 5000 miles on them. I broke a non drive side spoke at the cross point. The same thing happened on Friday.

That's an unusual place for spokes to break. Check all of your spokes at the crossing point. My guess is that you'll be able to feel a little "notch" on each one where one spoke has worn against the other. If that's the case, I'd replace all of the non-drive side spokes.

That's an unusual place for spokes to break. Check all of your spokes at the crossing point. My guess is that you'll be able to feel a little "notch" on each one where one spoke has worn against the other. If that's the case, I'd replace all of the non-drive side spokes.

+1.

Tension does not appear to be a problem here. The spokes are wearing out while rubbing at the cross point.

+1.

Tension does not appear to be a problem here. The spokes are wearing out while rubbing at the cross point.

Could that possibly be a side effect of lacing 2x? I can't imagine enough play in the spokes for them to wear significantly enough at the crossings. If the tension was higher, perhaps the spokes would rub less?

I talked to the builder today. He was very surprised that they were breaking there. He suggested going to a bit beefier spoke (Supercomp) and rebuilding the whole NDS. I am going to go ahead and do that. I went to my shop and picked up a new DT Rev spoke to replace the broken one. I will ride it for a few days until I can get to my spare wheels to substitute while these are gone.

While I was replacing the spoke, I checked the spoke tension (squeeze method), and they are definitely plenty tight. However, my LBS retensioned a few weeks ago when the first one broke, so that isnt to say that they were low before that.

When looking at the "Rub Damage" created at the cross point, there is some wear (anodization is gone), but I could not tell that there was any actual spoke material gone.

If the tension was higher, perhaps the spokes would rub less?

I'd think that increasing the tension would make them rub more. The spokes don't just cross, they interlace. Typically spokes bend around one another at the crossing point.