allen,
just staring at your frame for a while, looks great!
i keep wondering why you built it with such long chainstays. i am currently building a cargo bike, and the chainstays will be only a bit longer than yours, to get the rear wheel under the weight of the giant rack its going to have.
my main concern with the long chainstays is flex. i will be very interested in hearing how yours turns out. and what is the reason you designed it this way?