Icons Don't Resize with Navbar

[Foggalong]

There's a setting to resize the navbar like so

$nav-bar-height: 48px !default;

However going larger than 48 will not increase the size of the icons in the navbar accordingly and going lower than 48 will actually start to crop parts of the icons away. My guess is this is to do with the height and width being specified in the <svg element itself but I'm not certain.