Small wheel bikes have a reputation for "twitchy" handling that discourages riders used to bikes with larger wheels. But "twitchy" handling is the result of poor frame geometry more than wheel size. BioLogic™ II frame geometry is the result of almost 25 years of refinement by the product team at Dahon: a group that ranges from professional cyclists to physics Ph.D's. We've researched and tested every aspect of frame geometry from seat and head tube angles, to fork offset, to fore/aft weight distribution, to reach, to BB height. BioLogic™ II geometry is found on every one of our compact bikes and makes our bikes the most stable and secure handling folding bikes on the market.