FF -
Where's the section on duffel bags? Would you happen to know what size might fit the Swift?
Quick suggestion:
"Here is some things I do to my Dahon folding bikes to keep the wheels together when folded..."
A short length of parachute cord would work fine. Handy stuff. I use it for all sorts of tie downs, etc. Just cut it and sear the ends with a cig lighter to keep the nylon from uunraveling.