Tension anything and over a period of time it will stretch- Doesn't matter if it is a lump of plastic or a Spoke. And this is confirmed by my "Spare" Tandem wheels that I had trued and tensioned 3 years ago. 3 years ago they were perfect and sounded the same as the main wheels that I had done at the same time. Just gone down and checked them and they are not as taught as I would like them. Don't sound loose in any way- but definitely not as though they have just come from the builder.

Not many will have a spare set of wheels sitting on the wall for that long but the "T" no longer does the long enduros that I used to do and I have been lucky with the lack of damage done to the main wheels-----So far. These are top rate rims- top rate spokes and top rate Hubs and well proven for quality. Take the situation of poorer quality parts and Tensioned spokes will pull into the rim and hub aswell as stretch.

So from my experience and the advice of my builder- Check your wheels on a regular basis.

And the other set of wheels I have--The original OM ones from the OCR are sitting on the wall aswell. They were ridden for 6 months and were trued and retensioned after about 100 miles. Only about 2,000 miles on them but "IF" I were ever to use them again- they would need retensioning before use. No twang to the spokes when plucked- just a dull thud.