Quote:
Originally Posted by old3
I have found one fault at this point. (Finally!)............I'm thinking I was feeling the fork tubes flexing. It had a pumping feel at the bars, the forks couldn't seem to deal with the heavy side loading in that circumstance.
That has been the only oddity, and I don't know if more initial plushness would change it or if a fork brace would be the cure.......
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http://www.motorcyclistonline.com/fe..._third_motion/
"The third motion:
Barring a few exceptions, the front wheel of your motorcycle is steered and suspended by a telescopic fork. Steering motion is a simple rotation around the steering axis, and suspension motion an equally simple sliding motion between two pairs of tubes.
..........But there is a third motion that isn’t talked about much. Though there are springs inside the fork, the fork itself is also a spring. It allows the axle to move back and forth, perpendicular to the fork’s sliding axis (and, to a lesser extent, side-to-side), because the fork tubes flex under load, bending as load conditions change. And this flexing and recovering motion is not damped. The extent of flex is controlled by the strength of the components, but the movement itself is not controlled."
http://www.tonyfoale.com/Articles/Steer/STEER.htm
Fork braces can only stiffen the torsion or rotation of one fork respect to the other; however, they cannot do much (if any) to stiffen the sideways bent of the forks under lateral forces and accelerations.
Tubular shapes are the worst to resist bending forces and deformations (I-beam shapes are the opposite).
In order to eliminate the non-dampened lateral springiness, both forks would need to be braced against each other for the full length, what would defeat the telescopic effect.
They are braced at the top (triple-tree) and at the bottom (wheel bolt), but they depend on the tubes rigidity by the mid-span.
The main problem with that deformation is that it compromises the parallelism and hence the free sliding of the suspension.