Originally Posted by
twocicle
I can only relate my perception of this occurring in certain conditions only, where speed and handling aggressiveness is likely quite different than yours, so your experiences may vary.
Regarding wheel building:
That statement is very much false for metal spokes. Under load, spoke tensions can vary by quite a lot during a duty cycle. Spinergy BPO spokes are something of an exception as they are much more elastic and result in a more uniform tension throughout the wheel during a duty cycle (ignoring other BPO characteristics in this discussion).
To support your argument regarding aero spokes, you would have to believe that spoke gauge plays no part in a wheel's lateral strength. In many cases with an aero spoke, you are looking a sub 1mm thickness vs. 2.3mm in the fore/aft profile. This is done by taking a round 15 gauge DB section and flattening it. However, flattening an aero spoke profile does indeed influence its side-load characteristics and can be simply demonstrated by bending an aero spoke fore/aft, then sideways... there is a substantial difference in stiffness between these to planes whereas a round spoke is obviously going to have symmetrical characteristics. Putting a spoke under tension does not increase its inherent lateral strength.
I build all my own wheels. All spokes are elastic. The whole point of tensioning spokes to a particular kgf is to stretch them enough so that they are always under tension. It is not to stiffen the wheel, as a wheel with low spoke tension will be as stiff as one with high spoke tension. It is true that tension will vary slightly in the spokes of a loaded and rotating wheel. Complaints of broken spokes are almost always because too little spoke tension was used, thus the spoke fatigued at the elbow during its duty cycle due to loading and unloading.
Of course spoke gauge is a factor in strength and stiffness. However gauge is gauge and has nothing to with the sectional shape. Since spokes are always in tension, their column behavior is irrelevant. The problem with trying to build a stronger/stiffer wheel by using thicker spokes is that thicker spokes don't stretch as much at the rim manufacturers recommended spoke tension. Thus, having less stretch, they will change tension more as the wheel rotates under load and fatigue earlier, thus actually creating a less durable wheel. This is the reason that 14-15 double butted spokes work just as well for 120 lb. people on singles as they do for 350 lb. tandem teams. We just use more of them for heavier loads. A single 14g spoke will have a yield strength well over 500 lbs.
Spokes change spoke tension slightly due to the rim bending at the ground contact patch. Thus a deeper section rim will produce a more durable wheel for the same spoke count. And thus a higher spoke count limits changes in spoke tension by spreading the force changing spoke tension over more spokes.