Taking a motorcycle by bus

BY train -- Stop in Quy Nhon and the rest by motorbike.
But why don't you drive?  From Hanoi, there are 2 options the fast one is via the coast and after the Hai Van Pas ( Danang) inland or route 2 via Nghe An following the Ho Chi Minh route, scenic but slowly.
From Ho Chi MInh you've also the coast Mui Ne, Nha Trang and Quy Nhon and then inland via An Khe (  if you're going to Pleiku)  or you take from Ho Chi Minh the route via Dalat and Dak Lak.

The biggest advantage of the train over a bus is that your bike can remain upright.  On a bus it is horizontal so it has to have the oil removed and sometimes the handlebars.  Of course there is no train to Dalat but as suggested you could take the train to Da Nang, Nha Trang, or another coastal city then drive up. 

I am pretty sure that the train vs. bus thing was covered here in the past.  I tried giving it a search without success.  Unfortunately, multi-word searches don't work well on this site.

I have seen them load bikes into buses in hagiang, didn't know they drained the oil. It's quite common for people to put them on a bus or train.

KruChris wrote:

My next destinations will be the Hoghlands. I heard, the bus from Hanoi will take 24 hours and to get there from HCMC will taske 13 hours.

My great-niece and her friend rode his motorbike from Saigon to Da Lat 10 days ago.  It took them 9.5 hours with 4 stops:  breakfast, lunch, and 2 photo-ops.  They left Saigon at 6 AM, arrived in Da Lat just before 3:30 PM.