Joined: Nov 2006
Posts: 19,810
Likes: 597
From: NJ, NYC, LI
Bikes: 1940s Fothergill, 1959 Allegro Special, 1963? Claud Butler Olympic Sprint, Lambert 'Clubman', 1974 Fuji "the Ace", 1976 Holdsworth 650b conversion rando bike, 1983 Trek 720 tourer, 1984 Counterpoint Opus II, 1993 Basso Gap, 2010 Downtube 8h, and...
Between P-clips and extension arms, you can get a rack on that bike one way or another. It may not be pretty. The biggest issue will be with heel clearance; the rack needs to be as far back as possible.
Also, you might look into racks made specifically for folding bikes with 20" wheels (Dahon dealers will have them). My daughter rides a bike with 22" wheels, and to my surprise it fit a rack made for a 16" wheel bike.