How to detect bend in a spline or strait part of spline at position

[velikizlivuk]

Figured it out.
Move leaning logic behind base.Update() in my Motor Update() component and:
this.gameObject.transform.localEulerAngles = new Vector3 (this.gameObject.transform.localEulerAngles.x, this.gameObject.transform.localEulerAngles.y, this.gameObject.transform.localEulerAngles.z+sideLean);