I have been using a HW 60A 13.5T. The plastic center shaft seemed OK so far but I already broke a front knuckle, a rear C hub, a steering joint and deformed a crome plated rim so far. No direct full speed crashes, just occasional bumps. So I think the TT02 plastic parts are quite fragile. Now I tried to reduce their brittleness by puuting them into boling water and let it cool before using.