Hi marcag, what I am really wondering about is the effect of turning the probe left and right as you turn, it is seeing the air in a way that the rest of the system is not, if you see what I mean....the bike and rider are still pointing on one vector while the probe is facing another? I know this is a transient effect and probably of no great consequence in the scheme of things, but even riding down the road straight there are minor left right adjustments at the bars that do not occur at the head tube. Of course I am also implying that the probe is out in front far enough as well. Just thinking about the effect of left right movement off axis.

RChung hit it exactly (as always) in his next response " In earlier versions, it was mounted to the head tube so it wouldn't turn with steering input -- of course, one side-effect of having a long probe is that the observed yaw in turns is greater (think what would happen if the probe were 10 meters long and how the tip would have to sweep through a turn much faster than the base) "

So that is my question if you need to get out in front of the bow wave and to do so means more sweep of the bars, why then do most probes attach to the bars? Just curious is all.