Performing under the name Jaimi Starr, she cannot wear a helmet as this would affect the drag and she must keep a constant speed to beat the gravity that would otherwise pull her down.

泰利尔的艺名是贾米斯塔尔，在演出过程中她不能戴头盔，因为这可能会影响骑行。在骑行过程中她必须保持恒速前进，才能够克服重力不掉下来。

youdao

He is following a simple rule: Keep the angle of the falling ball constant in your vision and adjust your running speed accordingly.

WSJ: Matt Ridley on Gut Feelings and the Writings of Gerd Gigerenzer | Mind & Matter