Got it, you meant hide the top bar, not only top menu, right?
Two methods to do that.
1. Use CSS
Hide the top bar on global site
.site-header{display:none;}
Only hide the top bar on pages and blog posts
.single .site-header,
.page .site-header{display:none;}
2. Get rid of the top bar by hooks
remove_action( 'dgwork_header', 'dgwork_before_navigation',0);
remove_action( 'dgwork_header', 'dgwork_custom_logo',10);
remove_action( 'dgwork_header', 'dgwork_primary_navigation',20);
remove_action( 'dgwork_header', 'dgwork_top_buttons',30);
remove_action( 'dgwork_header', 'dgwork_after_navigation',40);
remove_action( 'dgwork_after_header','dgwork_page_header',10);
Thanks