In no way am I trying to contradict anyone's opinions when make this observation, just asking for an explanation from those that have some knowledge and experience with this. I can see how a fully or mostly flat arch causes the foot to pronate whether there is weight (force) on the arch or not. The foot simply slopes down toward the inside because it is not lifted by an arch structure: automatic pronation. But suppose someone has a well shaped but very flexible arch. The foot starts off not pronated. In walking or running the body weight is applied along the entire length of the arch and the foot flattens and then can easily pronate. But in cycling the power is applied through the ball of the foot. With no force being applied further back along the arch and to the heel, I don't see how there can be stress on the top of the arch to flatten it and then pronate the foot. And in any case when pronation does occur while cycling it seems to me intuitively that the support should be more like a wedge under the inside of the ball of the foot where the contact with the pedal and force application are rather than under the arch which is not in contact with the pedal and not participating in the transmission of force. What's wrong with this thinking?