Frequently broken s...
 

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[Closed] Frequently broken spoke.

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Had the local bike shop put my good hub on my good rim. They used new spokes.

Bit later the spoke broke. They replaced it. Broke again so I replaced it.

Now it's broken again.

What would cause a spoke / eyelet to keep breaking?


 
Posted : 10/01/2020 9:44 am
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Spokes are too short and aluminium nipples?

https://www.wheelfanatyk.com/blog/wheel-building-tip-no-9-succeed-with-alu-nipples/


 
Posted : 10/01/2020 9:59 am
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What would cause a spoke / eyelet to keep breaking?

That's a nipple breakage, not a spoke.

Longer spoke

Brass nipple

Check tension, especially compared with other spokes nearby.


 
Posted : 10/01/2020 10:02 am
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Is it anywhere near the joint in the rim? Is this flexing?


 
Posted : 10/01/2020 10:28 am
 Bez
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Bit hard to see from a photo where the tyre's nicely in focus but the nipple's blurred đŸ™‚

In the absence of a better photo, though, it does look like the spoke's too short. (Assuming that the spoke head has broken away and there's no exposed part of the spoke left sticking out.)

Also, is it the same breakage each time? You say "spoke/eyelet" breaking, but spoke and eyelet both look fine, seems like the nipple's failed.


 
Posted : 10/01/2020 10:33 am
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Looks like the head is broken off the nipple.

Check the spoke length.


 
Posted : 10/01/2020 11:47 am
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If the suggestion is correct, replacing the spoke with a 1-2mm longer one should resolve your immediate problem.

While you have the tyre and rim tape off you should also investigate the length of the other spokes. The concern would be that others may also be too short and not be sufficiently threaded into the nipples and therefore at risk of failing in the same way.


 
Posted : 11/01/2020 8:41 am
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What @bigyan said.

I suspect they used aluminum nipples that came with the spokes. Is the bike a commuter bike? If yes to both replace with brass nipples and maybe longer spokes if too short


 
Posted : 11/01/2020 9:00 am
 Bez
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Is the bike a commuter bike? If yes to both replace with brass nipples and maybe longer spokes if too short

FTFY


 
Posted : 11/01/2020 9:12 am
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@Bez, aluminium nipples are OK for normal use in my experience but when you commute on roads the salt destroys them. But I agree, I always use brass nipples. The weight saving isn't worth it in my opinion.


 
Posted : 11/01/2020 10:02 am
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Bike shop used the slightly shorter spokes they had on hand rather than order in a box of 100 of the correct size. Maybe to save time, or money, or both.

Unless you have a very good reason, never use alloy nipples, and always use double-butted spokes.

Check the rim bed of your wheel, the spokes coming from the rhs of the hub should all have similar protrusion or depth at the nipple, and ditto for the lhs. If they are not, odds on different lengths have been used, or you have wildly varying spoke tensions.

The ideal is what bigyan posted.


 
Posted : 11/01/2020 10:02 am
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It's a 29 wheel and the bike shop is purely road. Do road spokes tend to be shorter?

Will check to see how long their spokes are and then get it rebuilt at a better shop.


 
Posted : 11/01/2020 11:00 am
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Um


 
Posted : 11/01/2020 11:12 am
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It’s a 29 wheel and the bike shop is purely road. Do road spokes tend to be shorter?

Will check to see how long their spokes are and then get it rebuilt at a better shop

Wouldn't think road spokes would be any shorter, other than to account for (possibly) more radial spoke builds or builds with fewer crosses.

Before dismissing the shop entirely, consider it could have been an innocent mistake, one rogue shorter spoke made it into the bundle? Not great form for a wheel builder, but also not a hanging offence!

Have just built new wheels with Sapim aluminium nipples*. apparently harder and better coated to prevent corrosion and seizing. I always build with copper grease spoke threads anyway so fingers crossed!

*part experiment, part weight savings, part fancy anodised colours!


 
Posted : 11/01/2020 11:24 am
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Spoke length is determined by the hub, rim and lacing pattern. There will be a wide range of spoke lengths for 29 inch wheels.


 
Posted : 11/01/2020 3:41 pm
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If it has been the same spoke each time it does sound like you have one short spoke. Very often (nearly always with disc wheels) the spokes are different length left and right - they could have swapped a pair maybe.


 
Posted : 11/01/2020 3:48 pm