How is it that bikes have a diameter of 28 inches and that cranks are 170 millimetres long? It's all a question of evolution. When the first modern bicycles with chain drive appeared around a hundred years ago, the roads were bad. Big wheels roll over obstacles better than small ones, as every inline skater knows, and that's why the wheels of the new bikes were as big as possible.
Today, bikes can also be smaller! Or the crank length: any size would have been possible as long as the pedals were high enough above the ground and you could still get your feet on the ground. But 170 millimetres has become the standard. Why? Because men of average height were the key decision-makers in the technical revolution. And 170 mm cranks fit them pretty well.
The fact is, however, that the statistically average woman is only around 1.65 metres tall - much shorter than the average man. The logical step: downsize, and do so proportionally. Normal-sized wheels with normal-sized tyres and a normal wheelbase are evolutionarily quite mature in terms of their sizes, angles and lengths. They steer in a balanced manner, the happy average person sits comfortably on them and can operate all the components. The cycling world is set up for them.
Not for the little ones. Anyone who thinks that a lower frame height is enough to help little ones is mistaken. It's not just the frame height that needs to be right, but also its length. The handlebar width, the brake lever width and even the saddle size must also be reduced proportionally in order to give small children the riding experience that "normal" cyclists take for granted.
