I wouldnt blame mark. He just sells the stuff ita all made in russia. The Leo/Challenger2 tracks are problematic in that they are multipart assemblies like the real thing. a pad and 3 linkers for each full track link. The pins are quite tight honestly. Its the linkers that work loose or crack. Mine had a peculiar issue which aggrivated the problem but that is fixed and i havent had a problem since. Just check over the tracks before and after each run and give them a little look while its running. I wish the end linkers worked more like the real thing where a bolt in the center of it clamped it tight onto each pin.
My only gripe is that they arent "live" track like the real thing.