Resize Bezier Curve with shaped model


i have created a cylindric artistic structure by using an nurbs circle and a bezier curve.
Now i want to resize the model because it is so big.
However by changing the size of the bezier curve the whole proportions of the model change also.
How can i evenly resize a bezier curve in the y and z axis?

You will get a different result if you scale either the nurbs circle or the bezier curve in object mode and edit mode

So it is not possible in any way to change the size afterwards?
I have to choose the scale from the beginning?

Need Help!