Lox -
I've been searching around and counting the number of posters who like or dislike the Avons and recording what type of bike they rode. Thats how I got to thinking about the shock length.
I looked at 12 riders, both Bonny and Thrux, who posted about the Avons. All the Thrux riders disliked the Avons with 1 exception, marzydj, who had a Thrux but liked them. All the Bonny riders liked them.
Now I do not think the shocks cause the wobble, I just noted that the longer length seemed associated with the report of wobble. What I think we are seeing is the curved center groove is setting up an impulse and some bikes pick it up and amplify it into the bars. It is known that taller rear shocks and steeper rake translate into quicker more sensitive steering. Not every bike and rider combo will be the same, but it seemed to me the Thrux lenghth shocks weren't helping.
Thats how I came to the idea of switching back to my Bonny shocks. Perhaps my 250 lbs and forward posture comprsss my forks more than yours and make things worse. Perhaps there is another variable, like my 6'-3 height or perhaps my wheels have a slight out of round, or there is some other minor difference. Perhaps I ride on more crowned or cross sloped roads. I imagine the track you run on is more or less flat or banked rather than crowned or reverse sloped.
What I do know is I was driving on the NYS Thruway at 80 mph on a mile cross slope and the side to side impulse was coming through the rear tire pretty well and the bars were also wobbling when pushed up to high speed. I also know I got a dirfferent response from the bike when I put the shorter rear shocks back on - no wobble amplification, and solid feeling in the front. I'm going with it for now as its cheaper than throwing these tires away.