Hello All,
I saw this thread and I have some input here as the safety of the rider is so critical with this weave issue
1- everything that has been mentioned is valid ( too quick steering, not enough trail, CG and CP too close together, etc).
2- I would love to see the weather conditions for all the runs as pertaining to winds,,,, no other vehicle I know of has greater sensitivity to "Yaw Input" than a two wheel motorcycle streamliner....
The steering head bearings can be thought of as a "hinge" in the chassis in the lateral direction.
Any crosswind, whatsoever, will create an aerodynamic/mechanical instability that can build with speed until it equals,,,
thens exceeds the natural stability of the rolling chassis. Aircraft can swing their nose into the wind and "Crab"
forward, as they are a free body in a fluid medium, whereas tires in contact with the ground prevent doing this
in a ground vehicle....
I would have your team member aero specialist look at this ......
3- Do you 100% know for a fact the natural frequency of the chassis, and are you monitoring the vibrations in the chassis with your data acquiring system???
I have a simple method for finding the natural frequency, that works for any vehicle, if you would like to try it...
Good luck and be safe,
Robert "Smitty" Smith
Former Air Racing Crew Chief