I'm more interested in the road trip to the Cambodian border, by bike (do you mean bicycle, motor scooter, or motorcycle). Is it a long, rough trip; can it be done in one day? Would a bus ride be better? Can you do it for the purpose of renewing the 30 day visa at the border town?
You previously posted that you are interested in Đà Nẵng.
The common border run from this area (Đà Nẵng/Hội An) is to the Lao Bảo crossing.
It's 4 1/2 hours each way by car or bus, though I've heard of bikers doing it in 3 1/2 hours.
Most people do the 30-day eVisa run there by private car or a van arranged by a local visa agent.
Or, Is it better to go by plane to Phnom Penh or Vientiane? Thanks.
-@jwdtw.
That's pretty expensive because there aren't any non-stop flights from Đà Nẵng to either country.
Instead, an option would be to fly non-stop, round trip Đà Nẵng/Bangkok, currently available for about $165 USD
Only the airlines schedules can tell you if you could swing that on the same day.
However, some people who don't require a regular apartment are staying one month in Vietnam and one month in Thailand (or, Cambodia or Laos) and making that their regular routine, staying in an affordable hotel/apartment with kitchenette for a month at a time.
-@OceanBeach92107
Lao Bảo is quite a distance from Cambodia, though. It is, however, good for a crossing in to Laos.
The same crossing restrictions apply.