i have 4 kbc vr2's, a delta-77 and a tk-8... no problems with the visors on those kbc models... don't know about the strada, though. i had broken shields and installed then wrong so i always double check.

if the original never gave you problems before, i would have to begin with the blame possibly being user error... not what you want to hear, but the biggest variable causing problems with this exp, seems to be the shield change... again that is if the stock shield was never a problem...