Just a word of warning about your upcoming tour in Vietnam, I cycled from Hanio to Ho Chi Minh a couple of years ago and I wouldn't have wanted to do it on a road bike like yours. Some of the pot holes are big enough to swallow car tyres and a lot of the road surfaces are shocking.
I would strongly advise you to get a hybrid or mountain bike (not carbon fibre) and put semi slick tyres on that are no thinner than 32c. Continental Gatorskins would be ideal, I used the continental Sports contact (which have a Safety System puncture guarantee and still got a few punctures).
Also, your wheels really need to have a high spoke count (32 or 36); get someone to check the tension in the spokes before you go and it would be wise to take a few spare spokes (especially if you are riding 700c wheels).
Anyway, I don't wish to put you off as it is a fantastic trip but the first couple of days from Hanoi going south were not good cycling days as it felt like the heart of darkness; bad road surfaces, high volume of traffic, not very wide roads, everybody trying to overtake everyone in front at all costs, generally bad driving skills and every truck driver feeling obliged to burst your ear drums with their air horns, I saw a bus packed full of people veer off the road and down into a paddy field ending up on its side!
It may be worth you watching the Top Gear Vietnam special when they travelled through the country on motorbikes to get an idea of what it is like, even they missed out the section I mentioned above and put their bikes onto a train.
Not sure if you are going with an organised trip but they tend to be pricey. Me and my mate usually just rock up and do tours around the world without much prior planning. I quite like the spontaneity of doing things like that as you can adjust your plans according to whether you are enjoying yourself, however this doesn't suit all people.
Have a great time.
P.S. oops, just realised that you are in HCMC, guess you know what I am talking about.