I think, first of all we has to know, MX Tracks in EU and US are totaly different! A normal track in the EU is about 1-1,2 km (0,6-1miles) and the highest gear is the 4 of 5...
Because the FIM Rulebook say, max
average speed is 60kph (37,2mph) on a MX Race track....
And your tracks are much...