Originally Posted by
rpenmanparker
I hope you will permit me to correct a couple of misconceptions you exhibited in your post. First spoke unwinding is a serious problem, but it is not because it significantly loosens spokes. In most cases unwinding won't even be as much as a quarter turn, and that is hardly enough to noticeably loosen spokes. What it does is throw the wheel out of true. Still serious, but a different thing altogether.
Second, stress relieving spokes is a different process than releasing the windup in them. Both processes are important, but they are different. Stress relieving is done by squeezing pairs of partially tensioned spokes together to raise the micro areas of high stress above the yield point. Releasing spoke windup is done by compressing the rim in a fully tensioned wheel (in several steps around the rim) to temporarily loosen the spokes so they can unwind. When the rim is released, the spoke are pulled taut again. Then a final round of truing/tension adjustment and checking is required.
I mention this as it is important for novice wheel builders to keep these things straight. More information about it can be found by Googling "Sheldon Brown Jobst Brandt stress relieving"
If one spoke is wound up it will knock the wheel out of true... when 36 of them do this on a wheel that was probably under-tensioned to boot the effect is more significant.
These were on pre-built wheels that I had not checked... simply inflating the tyre caused them to become de-tensioned to a point where they would have tacoed under a rider.
When I build wheels I always do a final true and stress relieving with the tyres mounted and inflated... I have yet to have a wheel fail because of a build issue.