Sapper, I agree with your premise and do not believe it was a conspiracy "to make America lose". Belgium is the HOME of motocross and they are famous for their sand tracks. We've been there before and we knew exactily what to expect.
However, you can not compare Washougal or even Daytona to Belgium (although if Daytona was 4 times longer and a bit deeper...). Daytona ,although sandy, is a Supercross track. It is not as long or as fast or as rough or as deep as Belgium. Now if you head out into the woods 10 minutes from the track, you might find similar terrain - and that is why I suggested we send Floridians!
But, the Euros WERE racing on a different track than the Americans in the sense that they do 2 or more races in that terrain every year. Their tracks everywhere are very unlike the SX influenced outdoor tracks in America. Many train or live in Belgium or Holland just to practice in that difficult situation as it makes you a better overall rider. The Italian, Anthony Carioli, lives about 30 minutes from that very track and is there regularly. Jeffrey Herlings and Jeremy van Horebeek grew up racing local and their national series in that terrain.
If you follow European MX, the race previous to the MXdN was the German round of the series and K-Roc entered in the 450 class and posted a 3-2 to Cairoli's 1-1. That shows he is fast enough in Europe but in America, although always Top five, rarely top 3. That doesn't be he sucks, it just shows the difference between what the Americans do and what the Euros do. He is young and will develope. Barring injury, I expect him to be the 450 Champion in America.
