Hello klabu
Yessss, u may send u bike from cnx to bkk
It's easy :: the SRT now allows all bike sizes to be put onto trains in Thailand
Go to cnx satanic Rotfai, cnx trainstation approx one day before u want u bike been sent
The cargo is on the right side of the entrance
And get latest Infos there
The price for big bikes these route is 1980 baht
BE early at any station in Thai, as the bike is in a train the cargo car has vacancies
So it might be, the bike is put onto another train u booked your trip
But be shure :: it works, it's safe, and it's a great new option, to relax, save headache in buzzling traffic, saves rubber, saves benzine,......
Enjoy SRT with u motobike on your train or the next or the one before, as u bike might be at u desti even before you....!!!!!
Ps:::shipping is not possible fro Chiang Mai to bkk
Happy Thai train trips
Sandy