But his results were quite disastrous; he crashed out of four rounds – including the opening two – and missed two others due to injury. His best finish was 16th at Catalunya Moto2, and the young American didn’t earn a single point in the opening 12 rounds.Clearly not happy with the results, the AirAsia Caterham Moto Racing team has made the decision to replace Herrin with the Rattapark Willairot – effective immediately. The Thai pilot substituted for the injured Herrin at Jerez, finishing 19th.This decision, which arrived Friday, was also apparently a shock to Herrin, who has yet to release a statement.Speaking in the press release, Johan Stigefelt, AirAsia Cateham Moto Racing Team Manager, says “We have decided to replace Josh with Ratthapark. It was not an easy decision but it was necessary in order to try to bring better results on that side of the garage.“We are here to be competitive with two riders and the expectations were made clear from the start of the season. Unfortunately these goals have not been met, despite our best efforts and support to Josh.“We wish Josh all the best for the future and at the same time welcome Ratthapark to our team. I am happy that Ratthapark is joining us as we know he has the ability to battle for the points and can help us to gain good results, so let’s now see how we can improve for the final six races of the season.”Further analysis shows the bike can’t be blamed for AirAsia Caterham Moto Racing’s decision. The Caterham bike – a Suter chassis combined with the Moto2-spec 140-horespower 600cc four-stroke Honda engine – has finished fourth in two rounds with Johann Zarco at the controls.The Dwindling American GP GridWhen Herrin joined Moto2, it was great news for Americans, considering only two other stateside riders were competing in Grand Prix motorcycle racing at the time – Nicky Hayden (Drive M7 Aspar, MotoGP) and Colin Edwards (NGM Forward Racing, MotoGP).But things have changed; Edwards, who was slated to retire following 2013, began retirement earlier. The Texan is not competing in the second half of the season, though he may ride a few rounds as a wildcard rider.As for Hayden, he has missed the past three MotoGP rounds (Silverstone, Brno, Indy) due to recovering from wrist surgery. He is expected to return at San Marino next week, but there’s still a chance he may not. If this happens, no Americans will be present in Grand Prix motorcycle racing.Americans, who won over 80-percent of the premier-class titles between 1978 and 1993 (think Kenny Roberts, Freddie Spencer, Eddie Lawson, Wayne Rainey and Kevin Schwantz), have dwindled from the GP grids over the years. And with Herrin out of Moto2, things have just got worse.What will become of Herrin? We hope to find out soon, but he will likely make a debut in the all-new MotoAmerica series. This series will managed by the KRAVE Group LLC – led by three-time MotoGP Champion Rainey – in coordination with the AMA.Following the negative Herrin news,the creation of MotoAmerica this past week brings some positive, forward-looking news for American road racing. If managed correctly, MotoAmerica may just be the answer to more popularity among stateside road racing, which may equal more Americans ultimately transitioning to Grand Prix motorcycle racing.This is something desperately needed for not only the American road racer, but the American road-racing fan.