Since I purchased my D7 (from private party) there has been a slight wobble seemingly coming from the headset. I searched the Dahon forums and tried the fix suggested but that didn't work so I gave in and took it to the LBS that is a Dahon dealer. In less than a couple of minutes he had the problem solved! It was a simple adjustment (tightening) of the clasp that secures the handlepost. My D7 now rides solid and smooth, no wobble!