+1
I have three Ikea Dimpa bags total cost $12 plus tax.My Brompton fits into them perfectly,it has carry straps to carry by hand or on your shoulder.The bag is stronger than it looks and carries the bike without a problem.I don't doubt the Dimpa could be modified to work as a back pack if someone is looking for a budget bag.Attaching extra straps to it should not be that much of a problem and the material is really strong.