How about exploring http://www.waltscycle.com/trikes.htm for something
he likes?
One item listed is the Sun EZ-3, I weigh 270 lbs and ride an EZ-1.
Since March I have ridden 1800 miles on it, I hit a pothole and bent
the front rim slightly, after 1400 miles the rear rim split and I had to
get a new rim (have seen this defect on a bike friday with a 170 lbs
rider with 7000 miles).

One item i the industrial trike, he might consider that. At least the
prices are reasonable.

wrote:
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500 pounds is certainly a large individual. I'm giving the benefit of the
doubt that the OP was genuine and serious.

I am genuine and serious. This person is a very good friend of mine,
and he loves cycling. He used to ride an Electra Rally Sport. Apart
from a bent crank (yes, the cranks again), it held up well -- it even
survived a nasty crash -- but it's a single speed and the rear brake
has almost 0 stopping power.

Despite his weight, he can ride for long periods, and he was riding
almost every day. I've been on ~20 mile rides with him. Since
riding, he lost 10 - 12 lbs and he's trying to adopt a healthier
lifestyle. But cycling is still his love, so naturally it's his
choice of exercise.
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