I understand that on a long bike like the Big Dummy the rider's weight is about 50/50 front to back. As you load the rear cargo part of your long tail you would be primarily loading up the rear wheel correct?
So I'm a bit confused by the fact many BD/Xtracycle folks are using super heavy duty front wheels - 36 - 40+ spokes on uber beefy rims. Assuming you weigh 200lbs about 100lbs is on the front wheel and that shouldn't be affected much by how much cargo you load up in the rear. A typical 32H XC mountain bike wheel should be more than strong enough to deal with this kind of loading - especially on the road.
Just wondering why the super strong front wheels then?