bizarre bike wheel failure

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Originally Posted by CR94
Originally Posted by Number_35
... I think that this statement from the paper's abstract describes my situation:
"We find that increasing spoke tension increases failure load, unless the spoke tension is close to the buckling tension, in which case the wheel will collapse under even a small disturbance."

I think I had those spokes so tight that they exceeded the buckling tension of the rim. ...
Yes, exactly---as I stated back in the third post of this thread.
So you did! I expect no less from a fellow GLC driver.
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Received the Park Tool TM-1 on Friday, and checked out my new wheel this evening. Given that it's new and still straight, I figure it will provide a good baseline.

The 18 drive-side spokes averaged about 26.5. The lowest reading was 25.5 (2 spokes out of 18) and the highest reading was 27 (8 of the 18 spokes).

The 18 non-drive-side spokes averaged about 22. The lowest reading was 20 (1 spoke), and the highest was 24 (6 of the 18 spokes).

These are raw readings taken off the tool. Per the conversion table provided, the readings for a round steel 2.0 mm spoke convert as follows:

20 = 70 kg-force (700 N)

21 = 77

22 = 86

23 = 96

24 = 107

25 = 120

26 = 135

27 = 153

So it looks like the drive-side spokes are running at about 140 kg-force, and the non-drive side about 86 kg-force.

Because the force equivalents are non-linear, that's more difference than I would have expected between readings of 22 and 26.

I'll check the other wheels in our fleet - the front wheel on my wife's mountain bike is fairly new, so I'll use it for a front-wheel baseline, then it's on to the other bikes. I guess I'll never know, but would have been very curious to know how much tension I had on the old wheel before it potato-chipped. Thanks all for your input!
 
Make those tensions as equal as you can and take a large adjustable wrench or some other large "lever" and use it to twist each pair of spokes slightly against each other. Do that and check the tensions again. Wheel should last forever after that.
 
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