The world of motorcycling has quite a few safety rules. Good rules, like checking your tires and your chain and head light and so forth. They are not simply convenience checks; they are life and death items. Should one or more of these things not be right or within 'operational parameters,' fact of the matter is, the operator could die.
And so goes for loading a bike for a long trip. The more things placed on a bike, the more its handling will be effected. Sure, there are saddle bags and sissy-bars one can strap things to. But, that is not what the bike was really intended for.
From the 2007 Honda Rebel CMX250C Owner's Manual, page 29, “Your motorcycle is primarily intended for transporting you and a passenger.” There you have it, straight from the manual.
Perhaps on a trip, one should travel lightly, only bringing along a bare minimum. Traveling with too much cargo, or baggage can easily cause handling problems and quite possibly send you and it into the ditch at the side of the road.
Riding with too much baggage is no fun, even if you do manage to not crash. The balance of the bike is off, handling can be sluggish and aerodynamics can be all out of whack. Just when you think your baggage is stable and you have a grip on the handlebars as you buzz down the highway, that thirty pound bag of stuff strapped to the rear fender bounces loose, falls over and starts rubbing on the tire.
In short, excessive baggage can kill.
And, how does a passenger ride with all that baggage? Hop on top, grab a bungee and ride along? That is certainly not the safe way to go. Any operator who would allow this is quite remiss in his or her responsibilities.
Ride safe, ride happy and ride light.