In all my years of riding (nearly 40) I don't think I've ever had a brass nipple break. Many spokes...almost always at the head...but never a nipple.




Dan

Brass nipples break too. Just no where as common as Al ones. Generally we find that the spoke didn't enter the head of the nipple, it was a couple mms too short. Andy

+1, there is also evidence of corrosion on that nipple and its neighbor.

Why does that spoke have threads exposed below the nipple when the other one doesn't?

I had a feeling someone would ask that. It's because I tried to unscrew it just to see if it was seized or not. I was able to do that easily with just my fingers. None of the others have thread exposed. It's only because I twisted just a bit.

As I've read...this is probably due to the fact that the spoke is just a mm or two too short and didn't thread into the head of the nipple...as suggested above. (Although I guess it appears that way because I unscrewed it a little bit.) It isn't the highest quality wheel, but it's in the neighborhood of 10 years old and this is the first time that's happened.

Dan

Seems like if you screwed it back into position there would be spoke projecting into the broken off part?

Might be worth having a look at the spoke ends in the others even if it means sacrificing your rim tape

I experienced a similar nipple failure just recently when repairing a wheel. Head of nipple sheared level with bottom of slot. Ended up replacing all the nipples - false economy otherwise.

#1 cause of broken nipples is spokes that are too short.

Nipples are fasteners, not spoke extenders.

A properly built wheel will have the spokes at least penetrating the thickness of the rim...which is usually is about 1mm below the screwdriver slot of the nipple.

Quality nipples with spokes too short will hold up longer, cheap nipples will break sooner.

=8-)

This is a (real) wheel question, not meaning to hijack the thread, but how do you determine what spoke length you'll need when all you have is a hub and a rim? I will never build a wheel, but I'm one of those curious old codgers if that's okay.

First you do a net search for ”spoke length calculator”.
With a bit of luck, you might find one that already have your hub and rim in its database.
If not, you need to feed it some numbers.
The number you’re looking for for the rim is the ERD - Effective Rim Diameter. Sometimes the manufacturer either list it or even prints it on the rim. If that is not the case, further enlightenment can be found by doing a net search on ”measuring ERD”.
Oh, and you need to tell it how many spokes and what pattern you want.

Then you need some numbers for the hub. You need the diameter of the circle of spoke holes in the flange, and where the flanges are in relation to the middle of the wheel axle.
Feed this into the calculator and see what it comes up with.

Do note that this is the quick explanation of how to go about it. Further study is recommended before actually ordering stuff or attempting a wheel build.

And this sums up why I will never build a wheel LOL Thank you.

You use calipers to measure the hub and a couple of known length spokes set at desired depth in nipples + calipers to measure the ERD of the rim at a few spots (measure to INSIDE of bend). Calipers are cheap now and fun to own...

Then you use a spoke calculator.

Building wheels is fun, really... 'course mine are amongst the simplest with no dish. And I only need one :-)

(I've also lucked out that the factory ERD specs on my rims were correct - I did the measurement only to confirm them using spokes purchased on the assumption they were correct, while formally you're not supposed to trust factory specs)