I've made 5 sets of these saddles out of what I believe to be better choices in material. The guy I made them for is testing them on 2 jeeps now. I believe the original material to be Acetal (Delrin), which tends to get brittle with age. And if the Acetal is white in color, it is not UV stablies, and the sun's UV rays makes this worse. On the next batch of parts we make we are going to lessen the depth of the radius on the saddle, this should take care of the sag. I'm always looking for another test subject, so if some of you guys what a set, let me know.
Derek
derek@product-systems.com