navigation – Changing a navigation bar to display & # 39; contact us & # 39; only when scrolling

My navigation bar changes parchment – hides all links and shows only our coordinates.

Docked: http://prntscr.com/n3futl

On the parchment: http://prntscr.com/n3fuwm

Is it a good idea? Bad idea?

The goal is to generate phone calls and submit contact forms, but will it create a bad user experience?