Heel clearance is an issue with the racks that come on most 20" folders, so I would imagine those panniers wouldn't be usable. However, since they're an REI product, give em a shot in the store on your bike. They don't look like they hang as low as standard panniers. I'd be more inclined to getting the Kanga rack and the front luggage truss, and combine that with a rack-top bag for the rear.