[This is the first of what I hope to be many trail reviews for Vietnam. Keep in mind that mountainbiking has not yet discovered Vietnam, so most of these trails are used for other purposes, mostly by farmers, mountain tribes, or at one time used by hunters. The trails can be quite mucky fun, and many are remote and treacherous, and will not be found on any map.]
Ba Vi was (and still is) and army hill station, now with National Park designation because of its primeval forest. This is one of the mountain trails closest to Hanoi. A fuller description of Ba Vi can be found at www.nhandan.org.vn/english/landscape/19991231.html. Start in Hanoi for an all day ride (the road is paved, but rough and crowded with vendors and trucks) , or hire a car, park in SonTay, warm up for 10K of road miles, then start your climb. The hill station is a 1200m vertical climb over 10K, with 5-10 degree grades, all paved road. I estimate that there are about 15 miles of singletrack/walking paths off the main road, all of which lead to small enclave or farm plot, or Muong or Dao village, and two that lead to HoiChiMinh's pagoda and the Temple of the Jungle God. The grades can be outrageous, but like the views of the Red River, very rewarding. You'll walk your bike, no doubt. Leeches, poisonous snakes, and variety of other fauna are found, so tread lightly and stay on the trails. Drinks and basic food can be purchased at the entrance to the park and half way to the top at the army training center.
West out of Hanoi on Cau Giay highway towards Son Tay for about 40K. Left at Son Tay, bear right for about 10K more to the turnoff for Ba Vi National Park (you'll see the sign). Better yet, email me and I'll ride with you.