Modifications to the folding bike other than repairing it and changing its tires are disabled for technical reasons.
Eventually I’d like to make a generic system where you can fold up arbitrary small vehicles into an item and stash them in your trunk, limited only by your ability to lift them, but that’s going to be some kind of hairy coding, because you have to pack all of the data about the vehicle into the item somehow.
But yea, eventually a little go-kart thing you can fold up into a suitcase and stash in the trunk of your main vehicle should be a thing you can do.
Right now it’s restricted to the specific definition of the default bicycle, and it just stashes the damage levels of the various components.