Congrats on completing your trip
Folding bikes are ok for traveling short distances (e.g. to the next truck stop to get a hitch) but as you said not for real worldcycling (cycling all the way) with a lot of gear on bad roads. A bagpack is just too uncomfortable in the end. Did you like cycling with those big bags? Did you have problems with the bikes?
How do you manage to travel that light?
On my 9 month trip I had the following with me as clothing:
rainjacket, raintrousers, 3x glove (fingerless, windstopper, winter), 2x trousers (thin, thick), 2x underwear, 1x sandals, 1x shoes, summercap, winterhat, 1x fleece, 1 windstopperjacket, 2x shirt, 2x socks, 1x cyclingshorts, 1x buff
Camping: -15C sleepingback, matress, fuelbottle, stove (+spareparts), pan, spork, tent, waterfilter, waterback, repair-patches for tent and clothing, seamseal.
Bicycle: 1x spare tire, 2x innertubes, patches+glue, chain-oil, nuts and bolts, chain, 2x brakepad-set, tie-wraps, spareparts lowrider, chainwhip, multitool
Various: Camera, portable HD, cables, first aid, maps, 1x guidebook (in each country bought fresh)
All in all I carried 25 kilo (without food and water) and many consider that to be as light as you can get without entering the "dangerzone". What did you both cary?
Cycle the world,