I looked out of the window and saw Tim on his bike cycling along the road.

题目

I looked out of the window and saw Tim on his bike cycling along the road.
on his bike请教这里为什么用on 有没有具体的例子呢,

答案

在（公共交通工具）上
John got some sleep on the plane.
约翰在飞机上睡了一会儿.