First off I don't own a spyder but as I tell people asking about steering and handling related to 2-1 vehicles "physics is physics and steering geometry is steering geometry"
There is an equation that is universal related to steering and subsequent feel. In general your only adjustment is toe and this has only a mild effect on handling. Typically 1/4" positive is about right. Tire pressure as is recommended by the manufacture is set to 16psi or so, again only a mild influence. Anti-sway bar is a rather significant handling changer as a stiffer bar will cause a very positive improvement in the area of handling.
The busy front end as noted in the above statements is not directly related to steering geometry but more inline with aerodynamic design. The CanAm like the GL1800 goldwing have a rather large frontal area this design places the center of force well ahead of the center of mass. At speed and into the wind this will cause the bike to drift and even oscillate from side to side. The only fix is to first reduce the frontal area pressure by slimming down the design or increase the caster which will help but also cause more feedback while cornering.
Unfortunately neither option is currently available as caster is fixed and unless you replace the plastic aerodynamics is not an option either. The shell has been redesigned for 2015 so perhaps some tunnel tests warranted a change.
Personally I think more time in the saddle and a stiffer anti-sway bar is the ticket for now. I have over 106,000 miles testing and developing 2-1 configurations and I will testify the CanAm or any 2-1 design will out handle out corner most traditional 2 wheel motorcycles. Also avoid the tendency to over-inflate the tires as this is a common mistake that only damages the ride and tire life and offers no improvement to stability, actually it is quite detrimental to the drivability in most cases.
And that's all I have to say about that..........
First off I don't have 100k miles on three wheels.
I do differ on opinion though in regards to your steering geometry comments. I agree the Spyder is limited to toe adjustments, but these can be a huge factor. Some of the ways to dial in how a vehicle turns in is based on toe adjustments. In simple terms, toe out tends to wander, while toe in is more straight line predictable. Your 100k my indicate otherwise, but I will push my chips to the center of the table based on my track time in karts.
I can easily carry this over to the Spyder. Our machine was crap in the handling as delivered. Without using the laser, but rather a wrench, I decided by feel the front toe was not correct as delivered by BRP and made less than 1 turn on the tie rod. Pretty simple change, and based on driver input.
Prior to the toe change, there was no way I would consider loosening my grip, let alone take both hands off the bars. After the simple adjustment, done in two stages, I can go hands free at highway speeds (CC on) with no wandering back and forth.
As for the aerodynamics, I hear where you are coming from, but have a difficult time believing that at less than 50 mph, and cornering, the aerodynamics will foul the handling to that extent. If that's true, then with all the engineering formulas dealing with speed vs drag, yaw vs drag, aerodynamic drag and so forth, and most of these formulas deal with math to the square, at 80 these Spyders would be pretty unstable and wag their tail constantly.
Without much effort, I found this article that explains toe effects pretty good.
http://www.gomog.com/allmorgan/CAMBER_CASTOR_TOE.html
All the best with it.
PK
Hope it works out because a well running Spyder is, well, I won't be going back to 2 wheels! Good luck! :thumbup:
