If you are thinking of moving from HCMC to Phnom Penh, and want to explore the Mekong delta on a bicykle on your way, we can really recommend a three days guided tour with Vietnam Bike tours. Actually, the two first days are cycling, approximately 35 km day one and 50 km day two. The last day is the 6 hour boat trip from Chau Doc to Phnom Penh. The tour was well organized, the guide was speaking English quit well, he had a lot of knowledge, the bikes were good and there where a lot of interesting places to see, which you will not see from one of the boat cruises you can choose between. The only negative thing, is that it is a little to much driving before the start of stage 1 and after the end of stage 2. The cycling are mainly performed on small roads/paths with very little traffic and daily stages suitable for "normal trained" persons. The time we spent on the tour (three days, including the boat from Chau Doc to Phnom Penh), we think was perfect for our travel. Probably will many tourist find two days on the bikes enough to explore the Mekong, and it is a good way to enter into Cambodja.