Comment by SeanLuke

Having lived in Italy and used the btwin folder quite a lot, I can assure you there are lots of basic folders in its category and price range which are much better. I'd look into Dahon and Tern for a basic folding bike.

Folding bikes are complex and hard to make safely, and the folding mechanism is costly to engineer right. This means that the manufacturer of a cheap bike is either providing you with a dangerous folding mechanism, or is putting a lot of the cost of the bike into the folding mechanism, so there's not much money left for the rest of the parts. Either way, it means that cheap folding bikes are a bad choice, and the btwin folder is a good example of that.

As to patents: yes, there are patents.