Well, the weight limit of the mini velo would definitely be dependent on the materials and design of the bike frame and supporting components themselves. The wheels shouldn't be much of a factor. You'd have to inquire with the individual manufacturers as to what their specific weight recommendations are.

If you wanted my *opinion*, i'd say that most non-racing, non-super light, and non-folding bicycles should be fine for someone of your weight. Those ones from bikes direct weren't using toothpick components and didn't seem to be using ultralight tubing, and the Cannondale Hooligan is pretty much built up as a mini mountain bike on a heavy duty set of wheels and an oversized tube set. I'm only 73kg (160lb), but I took my Cannondale Hooligan off jumps for jollies, bunny hopped it everywhere I went and did a few quick trail rides as well, i'd say that bike is as solid as any mountain bike i've used.

If you wanted a folding bike, Bike Friday can make bicycles for your weight range. I'll definitely attest that my Pocket Llama was one of the finest riding bicycles i've ever owned, that little beast was extremely tough and very well designed, alas, expensive as well.

As for solid numbers on weight?

That's more of an age old problem with bicycles and heavier riders in general. There are a lot of people out there who are over 200lbs and always want to know if they can safely ride X or Y bike - but most manufacturers are very ambiguous when it comes to providing much of an answer. A handful state solid limits. Most others, you have to dig for info. If you find a mini velo and call the manufacturer up, you may get a straight answer or a bit of run around.

I wouldn't sweat it too much though. Don't buy a superlight with a handful of spokes on the wheels and you'll be fine.