ORIGINAL: HPI_Savage_RC
ORIGINAL: SAVAGEJIM
The plastic fomula that HPI started using for Savage X series is not as durable as the non-X Savage plastics.
What tests brought you to this conclusion? As far as I know, HPI uses 2 types of plastics: a Nylon polymer for high impact parts such as arms, bumpers, and shock towers; and what seems to be a glass filled nylon composite, which is used in areas where mechanical strength and rigidity are more important than toughness. I've done a few tests on both pre-X and X plastics, and both plastic types seem to be consistent in density, elasticity, elongation before break, and tensile strength from version to version.
I'm interested in hearing your side of the story, as I know you have materials science background, and would not simply throw a statement like that out in the open.
Its a proven fact that the X 4.6 series plastics are more brittle than the older 25 series plastics. HPI even says the forumla is lighter. If you wanted to upgrade the a arms to stronger ones the older a arms do not break near as easy.