Again, it’s a struggle to transport the goods carried (7)
I believe the answer is:
freight
'goods carried' is the definition.
(I've seen this in another clue)
'again it's a struggle to transport' is the wordplay.
'again' becomes 're' (prefix meaning 'again').
'it's a struggle' becomes 'fight' (fight is a kind of struggle).
'to transport' indicates putting letters inside (inserted letters are held or transported by others).
're' inserted into 'fight' is 'FREIGHT'.
'the' acts as a link.
(Other definitions for freight that I've seen before include "that's carried by rail and road" , "Goods carries by large vehicle" , "Charge for carrying" , "Consignment" , "Goods carried by a large vehicle" .)