I'd be concerned with the derailleur more than anything. on folding bikes the derailleur is only a couple inches off the ground and looks like it would be really easy to damage it. on small 20 inch wheels the derailleur is practically scraping the ground. so I don't understand why the vast majority of folding bikes seem to come with derailleurs instead of internal hubs. My Downtube 8fh is the only folding bike I know of that comes with an internal hub.