Nobody knows why Herrin struggled. Maybe not even him. You could argue that it was the bike, the tracks, the schedule, the culture shock, the crew, or just that Josh didn't get it done. My guess is that it was a little of each. It's pretty clear that he can ride the wheels off of a motorcycle. There's just more to the recipe than that. In any case, Herrin's struggle is exclusive to Josh Herrin and his particular situation in Moto2. It's not foretelling any other American racer's future.