Panda3D comes equipped with a special collision handler that is designed to keep characters at a fixed height above the ground, or cause them to slowly fall toward that height if they are too high. Unfortunately,
CollisionHandlerFloor doesn't have a component to ensure that our cycle's pitch will match the angle of the track. It's designed for use with a vertical character, such as a person, where that isn't so much of an issue.
To cover this lapse, we're going to construct our own system for ground collision.