Is there anything for a 4-7 day cycling tour in Vietnam that is part of a group, or a path that two of us can follow? Is there a popular route? Or any cycling adventures we can partake in? The beginning of the trip starts in Ho Chi Minh and we want to fly out of Hanoi.
I don't know of such tours (it doesn't mean that one doesn't exist). If you can't find one, I recommend local bike tours in Hue and Hoi An. I'd assume that other smaller cities like Da Lat and Sa Pa would also have local bike tours.
You maybe interested the highly rated Vespa tour (3-5 days). It's somewhat pricey but worth it. http://www.tripadvisor.com/Attraction_Review-g293925-d2004786-Reviews-Vietnam_Vespa_Adventures_Day_Tours-Ho_Chi_Minh_City.html
Hope this helps!
Update: Sumbled on this 3 day bike trip http://www.footprintsvietnam.com/Tours/Cycling/Amazing-Cycling-Mai-Chau-Pu-Luong-3-days.htm