Very famous single track in Altay.
The road is almost completely unpaved from Ust Kan. The gps file contains the single track and some dirt road part. The single track is around 20 km. Ther are a couple of big steps, being alone with a big bike is not a good idea.
Video of a step:
https://www.facebook.com/101nolimits/videos/445480705945647/