C21-2, AM49-3 and AM33-5 info:
AM33-5 long stiffener provides the maximal longitudinal stiffness of chassis.
Long stiffener doesn't reduce the torsional flex in case of using only one or two center screws.
So the the flex will be the same as with short stiffener that is screwed by the same one-two center screws.
But AM33-5 increases the longitudinal stiffness noticeable ( it prevents the chassis against longitudinal bending). This is the main advantage of AM33-5 especially for such soft chassis as C01AL-S.
Maximum longitudinal stiffness combined with an adjustable torsional flex provided by the alu stiffener is a key of our latest chassis flex control method.
AM49-3 is screwed directly to AM33-5 long stiffener.
C21-2 is a bit stiffer version of C21 with 3,8mm center hole instead of 6mm hole. So you have to use ST09 collar inside of the center hole of top deck instead of 6mm shims.
C21-2 and AM33-5 have the additional holes for 4 positions of AM49-3.