Something that is not obvious, but must be kept in mind when planning an air shipment, is the question "What kind of airplanes fly the route"?
Unless your motorcycle is really small (250cc or less) or you have taken it apart and crated it tightly, you can only put it inside a wide body passenger aircraft, such as a 767, L-1011, A-330 or A-340, DC-10 or MD-11.
The problem with other, smaller aircraft such as 757's (what Royal Air Nepal uses to Frankfurt), MD-80's, or A-320's is that the underfloor cargo compartment is not high enough to accept a motorcycle, unless is is almost fully disassembled.
If you are not sure about what kind of aircraft is used, or what the size limitations are, check with the airline, they will let you know.
Have a look at the picture below - this is a LD6 container that fits into a widebody, obviously a can like this won't fit into a narrowbody. FYI, if the aircraft has two passenger aisles, it's considered a widebody, if it only has a single passenger aisle in the middle, it's considered a narrowbody.