I bought two of these Citizen folding bikes, the Gotham 2 for me and I forgot what model I purchased for my boyfriend. The horror story begins when, as I am riding, the actual pin holding the hinge together on the front of the bike starts to work its way out of position and before I see it happening, the handle bar and support disconnect from the bike AS I AM RIDING IT---I almost got killed! I was able to retrieve the pin, re-insert and push into place but this is a frequent recurring problem and no bike shop will touch it. Finally, while transporting the bike in the car, the pin fell out and is lost for good. I am sure as the bike is several years old now I can't even get a replacement part. Does anyone know what my options are?