I'm 5'4". I ride a Bike Friday pakiT (small) very comfortably. I also have a Dahon Mu. In order to ride this comfortably I had to swap out the standard bars with swept back bars (which affects the folding a little bit). The reach from saddle to bars was too long otherwise for a comfortable ride. And, of course, the solution is not to move the saddle forward as that creates issues with the hips and knees and power. Because Dahon does not have an ahead stem that can be replaced with a shorter one (like a regular bike) you cannot change the distance to the bars, you can only sweep them back (or purchase an Aber Hallo adapter). If you have long arms you will probably be okay with a stock Dahon; if not, you may need to make a bar change and give up a bit of folding magic.