Fixing navbar when scrolling beyond a certain number of pixels
Cache your jQuery objects as @Abbas mentioned. Also, you could use toggleClass with a state switch:

var $catNavBar = $('#catNavBar'),
    $headerGbCont = $('#headerGbCont'),
    followScroll = $(window).scrollTop() &gt; 130;

$catNavBar.toggleClass('navbar-static-top', !followScroll);
$catNavBar.toggleClass('navbar-fixed-top', followScroll);
// etc..
$headerGbCont.width(followScroll ? 50 : 109);


Regarding magic numbers like 130, I would suggest that you calculate distances between elements and define rules based on the result rather than approximating when you should switch classes.