This looks like a rather old topic.
I think Columbus and Reynolds used to rate their tubing for rider weights with their high performance tubes for lighter riders.

Here is a list of wheels and weight limits.

As far as utility bikes... they can support a lot of well built. But they also aren't made using paper thin carbon fiber tubes, and wheels are built for the job at hand.

I have no doubt the rear tire on my cargo bike would carry as much weight as I could support the bike upright with. However, I'm not sure about the axle, or perhaps other components on the bike.