I'm looking at getting a folding bike for when I return to uni for my PhD and am trying to give myself plenty of time to decide. Was hoping you guys could give a bit of help.

I'd like something as simple and light as possible and so I'm thinking a single speed. I like the look of the bike fridays for their 20" wheels and ability to fold without removing anything, also I'm hoping I'll be able to get a lightweight road frame with disc brakes as they'll all custom. If there's any alternative that fits this description please let me know as I'd love to know what else is out there.

I'm wondering though what the lightest anyone has managed to build a bike friday is. Do you guys think it would be possible to get one down to under 7kg?

Thanks for any help you can give.