Originally Posted by Bacciagalupe
Personally I don't see much of a market for non-folding mini bikes, it's a niche product. For most people, the disadvantages of small wheels are a good trade-off when you can fold the bike but not worth it otherwise.
They're very popular in Japan. Just do a google search for "minivelo." There can be a big difference between the performance of a bike designed to fold, and one designed for speed, but with smaller wheels. The ride and performance of a folder is not necessarily represenative of small-wheeled bikes in general.