I thought the rocky, abrasive trails of central Arizona were tough. Just take a look at this video from (what I am assuming is) the Frech alps. High-speed switchbacks. I would not ride this thing on your bike.
Mondial Du VTT Descente de Venosc caméra embarquée
Uploaded by 103TuRtLe.
EDIT: On the second watch, I still think AZ [...]