Just thought I’d report back to you in regard to how the carrier is holding up. And the answer is excellently ! We are now in Karratha after travelling up through the Centre (Camerons Corner, Strezleki, Oodnadatta) to Alice (East and West McDonnells), and on to the Kimberley via Tanamai Track. Through the Gibb River Rd (including Kalumberoo to the north) and down to Broome and now the Pilbara via every corrugated scrappy dirt road we could find. The carrier hasn't missed a beat!
From an engineering point of view, the survival of the rack with two bikes over 4000km of corrugations is truly impressive.