Perfectly tuned to every size: Size-dependent geometry and frame stiffness Chainstay length and seat angle are adjusted to the frame size (the seat angle becomes steeper and the rear end grows with increasing frame size), so that every rider, regardless of their height, receives the same balanced geometry for the best riding behavior. And since taller riders impose greater loads, we adjust the stiffness for each frame size. This ensures that every rider experiences the same perfect ride quality.