Hi,
The breakpoint relies purely on Bootstrap. So you have a couple of options:
1) Either downloading a customized Bootstrap version from here:
http://getbootstrap.com/customize/
you need to edit the media query here:
http://getbootstrap.com/customize/#media-queries-breakpoints
* Note that this solution will affect all Bootstrap components on your page, not just your navbar.
2) Or manually editing “bootstrap.css”. I have posted an example of all the media queries that need to be edited in the default Bootstrap CSS if you would like to change just the navbar breakpoint from 768px to 991px here:
http://www.smartmenus.org/forums/topic/adjusting-the-navbar-breakpoint-bootstrap-3/#post-1765
Please let me know if you have any questions.
