only 1 thing I would change: the corner [attached] seems to be a bit sharp, it just seems to sudden from the rest of the course (just because its on a straightaway.) Other than that good work!
It actually has to be a sharp corner, because it has a jump crossing it. So that section has to be a bit more narrow compared to the overall track. I tried to rework that section the best i could and i guess it turned out a bit smoother... Anyway, give it another try and tell me what you think! Oh and thanks for all the positive feedback so far!