"Above all, we want the joy of movement for young athletes" 👍 THE GEOMETRY OF THE FRAME DOESN'T MATTER - the construction of the frame is essential for the comfort, health and safety of the child. I DO NOT HAVE CHOOSING THE WRONG SIZE, IT IS ONE - the child's first impression of the bike and riding it is absolutely crucial. A bad, non-fitting frame and the associated bad sitting on the bike can have a detrimental effect on children's musculoskeletal system and their proper development. DESIGN DOESN'T MATTER - design is a bit of a complicated thing, it must appeal to both parents and children themselves. ) I DO NOT HAVE CHOOSING THE WRONG SIZE, IT IS ONE - the child 's first impression of the bike and riding is absolutely crucial. The wrong choice of frame size often disgusts the child because the bike is simply not well controlled. Rather than a child, the bike then rides the bike by its rider. Not to mention that a non-falling frame and the associated bad sitting on the bike can have a detrimental effect on children's musculoskeletal system and their proper development.