Originally Posted by Nordo

I think all the track racks have the same width track and the same latch bar. The difference is the length and how they attach to the bike. My bag is not as long as my rack but it works fine.

This is the rack I have, I got rid of the flat steel attachment hardware and made my own from aluminum tubing:

TopeakŪ Cycling Accessories ? Products - Explorer Tubular Rack (w/o Spring)