We have just built our first pair of wheels using the NoTubes ZTR Alpha. We had some issues getting the tension right as when the tyre air pressure is increased to riding levels the spoke tension drops away as it compresses the rim. Increasing the tension further just stretches the alloy round the spokes holes.... Any advice on building with these or can you refer us to anyone with experience please?
Web: Strada Hand Built Wheels
Not having noticed such a problem, I forwarded his comments to Velonews's esteemed technical editor and tubeless expert, Lennard Zinn. He was kind enough to reply:
I haven't checked spoke tension on the A340s since putting road tires on them. At 28psi with 'cross tires it wasn't an issue.But yes, we always notice a decrease in spoke tension with tire inflation. Eaton, for instance, builds the rear wheels off dish so that when the tire is inflated the dish is correct.
Eventually, I heard back from Jonathan over at Strada:
Here are photos [above] from recent builds including these ZTR Alpha rims onto our own label hubs. These were built for a light climber who wanted to try a tubeless setup. He completed the Marmotte 2011 on them which is great. Getting the spoke tension right is tricky and we have decided to sell them only with a new pair of Hutchinson Fusion 3 tyres fitted so we can tune them with the tyres on to ensure the best finish.Conclusions
To be honest, I still don't know what to make of the whole spoke tension issue. I have now converted at least eight different road wheels to tubeless over the last five years, but none of them have had any spoke tension issues. I have a Park Tools professional truing stand at home, and I like to keep my wheels true within a fraction of a millimeter, so I think I would notice if it screwed up any of my wheels. That said, I trust experts mechanics like Lennard Zinn and professional wheel builders like Jonathan at Strada. If they say it is happening, I believe them. Fortunately, it does seem that this problem, where it arises, is surmountable.