Amtrak's bike boxes are pretty big, so you shouldn't have to make any heroic efforts to fit most bikes. Their Pacific Surfliner trains runs have three bike racks in each car, or maybe it's three at each end of the car (I can't remember). If you're on that kind of train, you just roll the bike onto the train yourself, with no box, and hang it up. It might be good to lock it to the rack anyway just so someone can't fly out the door with it at one of the brief stops. If you have panniers and other luggage, you can usually put it on the floor under the bike, but there would be a reasonable limit to what you would be allowed to put there. The rest should fit in the overhead storage compartments at your seat. The travel on these trains is very pleasant, with loads of room and very little noise compared to an airplane. We've been on one of their Coast Starlight trains too IIRC, which seemed smaller, older, and not as pleasant, and they didn't have the bike racks, meaning you would have to box the bike. Their website is amtrak.com . Note the spelling-- two a's, no e.