Hoi Chi Minh City

Making an impromptu trip to Hoi Chi Minh City in a couple of weeks and
taking my road bike with me. Other than fitting some stronger wheels
and 25mm tyres I'll just use it as is. I'm going to be making day
rides which start/finish in the city. Any suggestions, links, tips?
All feedback welcome thanks. I'm trusting that i can pick up a street
map once I arrive, but I'm having trouble finding any road maps of the
surrounding area. Any ideas or online sources? Thanks again. Nige.