Proper use of the Sapim "Super Spoke"

[bm0p700f]

Royce will do this I think drilling for 2.0mm if you ask cliff nicely. He may think you are mad though.

[WMW]

The super spoke is 1.8mm dimeter at the elbow and is therefore less fatigue resistanced than a CX-ray also spoke holes that are 2.6mm dimeter will result in more movement of the spoke and faster fatigue.

I don't think it's a problem. The spokes shouldn't be going slack anyway, so the elbow will remain embedded in the flange under some tension. And if you are worried about it you can use spoke head washers.

I agree that the round version is useless... mostly because I believe any special expensive spoke needs to be aero also.

And in that theme the CX-Super might have some practical use for NDS and front wheels, but I'd like to see a bigger weight reduction to make them worth the trouble.

[Zoro]

...material modulus of elasticity...

Modulus of elasticity and elastic limit are two things to consider.

One is how "stiff" a material is (how much force is required to move a distance) and the other, at what force will the material no longer be able to return (elastic) to where it was. Common speak - it got over stretched.

Both are real and different aspects of a spoke wheel. At some tension (too lazy to look it up), the spoke will permanently elongate and not return to the original length.

A spoke may have a higher elastic limit, but also be more elastic (less stiff) - Titanium for example.

[bm0p700f]

All spokes permanently elongate when building though. Even Race spokes when I have finished grasping pairs of spoke show quite a big tension drop. They must have stretched permanently as if I de-tension and re-tension I find I can no longer get a tension drop by grasping pairs of spokes. Super spokes will stretch more though but this does not weaken the spoke it is necessary as when torque gets applied the spokes will stretch so best get it out of the way when building.

[TheKaiser]

Don't you think that the detensioning after squeezing pairs of spokes is more likely due to nipples bedding into the rim, and spoke heads bedding into the hub flange?

Spokes do exceed their elastic limit too but more in terms of following a straighter path out of the hub shell than an actual increase in linear length. In other words, spokes go from slightly bowed to more straght, which increases their effective length without significantly effecting their linear length. Perhaps that is what you meant, sorry if I misunderstood.

Also, it goes without saying that eyeletted rims offer another point of potential bedding.

[WMW]

I think spokes will also elongate a little from relieving internal stresses... but I agree that most of the permanent length change is probably from the plastic deformation of all the components as you describe.