http://members.efn.org/~cat/html/longhaul.htm
Human Powered Machines Longhaul cargo bike. Load is between the wheels and low, which makes for very good handling even with huge loads. We've got three of these and use them every day. Rated at 200# plus rider, I've put 400# up front with 200# of me on the saddle. Mine is fully speced out with a mix of Phil/King/XTR parts with some downhill cranks and beefy rims.