The South of Vietnam excluding Mekong makes a so much difference in scenery, people and geography. The change can be from a bustling city to cool highland with elephant, hill tribes and their special culture, from a mountainous roads to so flat road along the coastal line, from endless coffee plantations to the spectacular view of primitive jungle with high cliffs. The difference is then very much worth of a biking trip that you can see all this at your pace, made by your pedals.
Enjoy the biking to waterfalls, the cool temperature at 1000m elevation, elephant ride, forest trekking, tea, coffee and cashew nut plantations, primitive jungle biking, hill tribe cultural values, and the like.
The road is of challenge, but extremely beautiful.