I recently bought what I believe is a (2nd hand) Dahon Boardwalk D6 from a guy at the German equivalent of Craigslist ("Kleinanzeigen") for 60€ ( ~$82).
The 2 of us tried to fold it together, but the most we could do was 90° (it took us like 5 minutes) and it was a pain to unfold. The spring seems a bit rusty but the... pin comes out, the frame just doesn't fold one bit. Could it be just a bit rusty? Did anyone have a problem like that? Seems to be similar to this guys problem, but it's another model.
The folding of the handle bar and everything else works fine, that's why I bought it. The guy at the local bike shop tried to put some oil spray inside but it didn't do anything. I don't really wanna invest a lot but would rather do it myself, if possible.
This guy bought it 2nd hand himself, that's why I can't say for sure which model it is. The registration says DAONH0584 and the sticker says "Hon" instead of Dahon. It's not the latest folding mechanism but it kinda looks like this one with 6 gears (and green...): https://commons.wikimedia.org/wiki/F...hon9av26st.JPG
I'll upload a photo later. Maybe someone can tell me which model it is too