I've been meaning to get a bike bag for a while, as you can't take bikes on Japanese trains without one. The normal ones are made for road bikes but I recently found out that Tioga made a BMX-specific one, so picked mine up yesterday:-
This should give you a better idea of what it is:-
& this is what it actually looks like with a Crupi race bike inside:-
I don't think Tioga had in mind a Pro XL racing frameset when they designed it because it was a bloody tight fit! I took the pedals off to make life easier and then took it on its maiden outing today! I got some bloody odd looks along the way but it worked, so job's a good'un!