# Rear wheel keeps going out of true



## sdeeer (Aug 12, 2008)

Looking for the best course of action.

I had a powertap pro+ hub rebuilt to a HED C2 with 32 3x double butted spokes. Rode it ~150 miles and then brought it back to the builder as instructed for a tune up. Within a few weeks some of the NDS spokes became loose and the wheel went out of true. I brought it back in and it was trued again. This true lasted longer under similar conditions of riding and me now aware of maintaining NDS spoke tension, but it is out of true again. The DS spokes seem to be OK tension wise.

What should I, the original builder, or someone else do to get the NDS spokes to stop going slack and ultimately make the wheel stay in true for a "normal" amount of time?

Thanks! 

[Note: I have not trued wheels myself (at least that are this far off), and while I am becoming more knowledgeable in wrenching, I am not comfortable doing more major wheel build / work just yet]


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## Mike T. (Feb 3, 2004)

As you're probably aware, all rear hubs have asymmetrical flange spacing (because of the need for cassette spacing) and this leads to a difference in tensions between DS and NDS spokes. The lower the tension, the lower the pressure on the nipple threads and the more chance for those nipples to unscrew during use. Probably someone willl respond who knows the tension ratio for this hub (I don't) and it might shed some light on the NDS spoke tensions as being the culprit.

Of course if the DS tension is high enough, the NDS tensions might be high enough to prevent the nipple loosening. So we don't know what DS tension your wheel person is using.

Another probably cause might be that the wheel person isn't performing spoke wind-up relief when building & re-tensioning the wheel.

Read my site and it might shed some light on the issue.

I have an issue with a wheelbuilder suggesting that "[it should be] brought it back to the builder as instructed for a tune up". If in their experience this is necessary, then they might have a history of not building wheels properly. Properly built wheels don't need re-tensioning. After all, what do internet custom wheelbuilders do? Have you ship them back after a month?

I would also suspect anyone who suggests using loctite or other thread glues to keep the nipples from unscrewing (unless it's been proven that it is the only way you will stop this problem with this hub geometry). That would only cure one by-product of low tension (nipple unscrewing) - it won't cure the early metal fatigue of your spokes due to low tension (caused from wild tension swings as the loaded wheel rotates).


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## dcgriz (Feb 13, 2011)

From your description on what is happening, I would say that you dont have equal spoke tension around each side of the wheel. I am suspecting the there is great variation in spoke tension between spokes and although the wheel spins true on the stand, it starts coming out of true as soon as load is applied and the spokes try to equalize their tension with each other.

So equal spoke tension would be the first thing I would look at. At this point it may be best to loosen up all spokes and retension the wheel properly. When this is done make sure the spokes are stress relieved, are free of windup and are properly aligned with the hub flanges.


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## Mike T. (Feb 3, 2004)

And of course sdeer can check for unequal tensions by simply plucking and listening.


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## cxwrench (Nov 9, 2004)

Mike T. said:


> I have an issue with a wheelbuilder suggesting that "[it should be] brought it back to the builder as instructed for a tune up". If in their experience this is necessary, then they might have a history of not building wheels properly. Properly built wheels don't need re-tensioning. After all, what do internet custom wheelbuilders do? Have you ship them back after a month?
> 
> I would also suspect anyone who suggests using loctite or other thread glues to keep the nipples from unscrewing (unless it's been proven that it is the only way you will stop this problem with this hub geometry). That would only cure one by-product of low tension (nipple unscrewing) - it won't cure the early metal fatigue of your spokes due to low tension (caused from wild tension swings as the loaded wheel rotates).


^ This ^
There should be no need to 'touch up' wheels after a 'break-in' period. When the builder finishes a wheel it should be done...ready to ride. Just like a mechanic finishing a tune up, no 'adjustment' should be needed down the road.


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## sdeeer (Aug 12, 2008)

So is the solution to have a different builder/mechanic loose the spokes and perform spoke wind-up relief when building & re-tensioning the wheel?

and check for equal tension before they give it back to me.

I have been using the plucking to try to keep it close, but I must not have it equal or the original build is too off, because it keeps going out of true / tension.


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## Mike T. (Feb 3, 2004)

sdeeer said:


> So is the solution to have a different builder/mechanic loose the spokes and perform spoke wind-up relief when building & re-tensioning the wheel?


I can't answer that as I can't evaluate the job done on the wheel. Once around checking the tension tones would tell me all I need to know though. Yeah tones can't (won't) be 100% equal due to the need to true the wheel and that few rims are 100% perfect but the tones should be close. Even my own wheels are off a little bit - and that's ok.


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## Z'mer (Oct 28, 2013)

The problem could also be that the DS tension was set too low. If so, then the NDS tension is way too low, causing your problems. If so, the only cure would be to re-tension all the spokes on the wheel as others mentioned. 

There is a $5. iphone app that supposedly uses the microphone to record a spoke pluck tone and then tells you spoke tension. Have not tried it, but it may be worth a shot to at least tell you if you're in the ballpark.


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