Very interesting, good information there, thanks Syklist. Are you the author of those articles?
Would you still get tyre clearance problems with a narrow tyre such as a Kojak?
Yes I am the author of those articles. As regards clearance with Kojak tyres: I have no idea,
I need Schwalbe Marathons on my Brompton
However, I have added a post about the clearance between wheel/hub and rear forks.
http://mistymornings.net/blogs/mm/?p=191 As you can see, it is all a bit of a tight fit.