Sistem Rating Lintasan Bersepeda Gunung

Tunggu tanggal tayangnya......................


Referensi:

1. Trail Grade - UK Forestry Commission
2. Whistler Trail Standards
3. Trail Difficulty Ratings & Signs - IMBA
4. The Best Mountain Bike Trails in the World
5. Bike Trails in the World with Rating
6. CTC off-road Trail Grades
7. Trail Guides
8. A National Standard for Mountain Bike Trails - Initiative