In 2 days time there are some itneresting rides to do. West of Hanoi is a place called Mai Chau, which gives a feel for the countryside and you have to cross a mountainpass (not too steep) for it. It's about 120k one way.
too bad you don't have time for a longer trip, the northwest route to sapa, via the same Mai Chau, Moc Chau, Tuan Giao, Lai Cau, Pa So and finally SaPa, is fantastic.
Running along the chinese border in the northeast is the most brilliant stretch of paved road in the whole of the indochinas. After 8000k in the area (on a minsk) it's still our favourite. You'll need 3 days minimum though
Get your Minsk from Cuong in Hanoi and try to talk to anyone of the minskclub or www.exploreindochina.com
for more info and inspiration
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