I leave here a link with all the circuits for SuperMoto and 80cc that I have.
They are all GP Bikes and Kart Racing Pro, and all are public, but in other pages, so I have compressed and uploaded in this .rar to make it easier.
They are almost 130 circuits, and occupy a lot of space, do not frighten them;)
Extract the folder Supermoto, inside the folder gpbikes / tracks /
Then, inside the game, when you select the circuit, up to the right of the screen, select Supermoto, and thus you will have all the circuits ordered;)
NEW LINK TRACKPACK
Thank you Jose!!