When my buddy bought a bikeE, I put a 406 - 20" on the back to replace the one filled with solid rubber. The front was 16". The size in "mm" should be on the side of the tires.
Don't forget to put them on Craig's List. Chances are you can unload them locally, so people can come and check them out (no shipping). If they need to be adjusted to work properly, The Bicycle Garage at the corner of Blacow and Mowry works on my recumbent.
What is your asking price for each one?
Last edited by Dchiefransom; 07-11-09 at 11:17 AM.