Both. Mechanics have told me that they see all sorts of folders with problems, including sheering. Damage to the headset will set you back $100, but damage to the frame...

I would imagine that Bike Friday would replace the frame if it did happen. They use 1 1/8" headsets, yeah?

While they didn't do a good job with their re-design, I do think that Dahon is heading down the right path by being proprietary for some things. A stronger headset and narrower hub (to prevent spoke breakage) both make good sense to me.

I've never had problems with either, but it's frustrating using standard parts. Who wants a 32 hole hub on a small wheel?