Answer is YES to: Did you reach that speed before fairings?
It has been at this speed earlier, without the shake. Certainly the fairings helped to get even faster,.. but shake occurred before reaching the new area.
I believe it is a wheelpant issue,... just wondering if it is simply time to recheck the "final" alignment, .. or a gap,.. or the shape/angle of the tail of the intersection fairing (which I added just a bit to). Also I ended up making the holes in the nose gear slightly larger in order to accommodate my tow bar
other thought was possibly the gear/fuse intersection as there is a small gap there... but I do not hear any banging, or see any cracking around the screws