The classic loop starts in Ha Giang, passing through Quan Ba, Yen Minh, Dong Van and Meo Vac before returning to Ha Giang. In the absence of satisfactory public transport, this route is best travelled by motorbike (or hire car with driver). Allow 4 days: you can't drive fast on these roads that play leapfrog, especially with small bikes, and there are plenty of opportunities to stop.