Ive posted over the world using these, they are fast and use DHL, you have to pack it in a box upto 4 cubic feet, so a box around 1m long, 18 inch high and 10 inch wide. Ive been over box size limit slightly before and its been ok, is the bike valuable? they will insure upto £500, but you can find other insurers if reqd
check out this site, thought everyone knew of it
http://www.parcel2go.com/