Bringing a bicycle into saigon via airplane

Which lane should i cross? Declare or nothing to declare?

If declare, how much is the tax rate?

Much appreciated!

I brought a bicycle into Vietnam about ten years ago.  At the time I was on a short trip as a tourist and the bicycle belonged to my traveling companion who was giving it to her family.  We removed the handlebars and seat and shipped it in a standard bicycle box that companies like FEDEX and DHL have available.  I don't recall any problems at entry but the bicycle was used.  If and only if you are asked, and as long as it is truly used, you should make that clear and there should be no duties.  A brand new bike might be different.

well noted. Thank you

Nothing to declare.. always.....  go some bicycle shop and ask them those boxes and pack it.