Broken Spoke Question
So, I'm a commuter and I ride my Pugs every day, Yesterday on the way home I noticed that my wheel felt a touch different, so I took a peek and noticed a distinct hook in the rotation. Broken spoke.
I didn't hear it go and the hook wasn't too back so I finished out the commute and when I got home to check it out the spoke was broken at the nipple, not at the bend. Every other spoke I've broken has been at the bend. I've never broken one at the nipple.
I took the wheel in to REI to have it repaired so I could ride this morning and asked the shop guy what might cause this type of break. The only answer they could give was that I must have hit it with something or hucked a curb a bit too hard.
I know this isn't the case. No off road. No sticks or rocks that I can recall, and when commuting I have a nice, completely paved trail with no curbs or other drops.
So my question to all of you is what might cause this so that I can prevent it from happening in the furture?
Bike/Wheel/Tires have ~688.83 miles (give or take a tenth of a mile or so...)
Tire - Endo @ 15PSI
Weight of rider: ~260
Weight of paniers ~30
Any thoughts would be appreciated.
Poorly built wheel....
Uneven tension in spokes due to poor rim quality...
Nick in spoke during assembly...
NIpple "frozen" in rim not allowing for some movement.
And with your weight, low strength spokes....
Aloha, always a hard one to answer. I too break spokes from time to time at the spoke nipple. However, I also get a lot of sticks and rocks hitting my spokes though in most cases, the spokes are not broken at the time.
The only explanations I have are:
The threaded part of the spoke is a weak point. It is narrower and has "sharp" edges which can migrate cracks easier. Add to that, most times there is some twist to the spoke from the truing process. Imagine a "nick" in a paper clip and you take a couple of pliers and pull and twist on the ends. The paper clip will have a tendency to break at the nick.
Anyway, I know it's not a total explanation. Hope it's just a one time occurrence.
The process of machining the thread causes micro cracks...
...usually it doesn't matter, but once in a while, "crack"
Another cause of breaks at the nipple is not enough thread insertion. Though, to be fair, that is much more common with aluminum nips versus brass.
Thanks for the insight. I guess I'll just keep riding it and hope I don't have to replace any more anytime soon.