On mobile, a link bar is somewhat equivalent to having the main categories showing directly in your desktop header menu.

 

A bit of data

 

So it’d be fair to assume that the impact of having a link bar is going to be higher than that of a categories section below the fold.

 

My advice is this

  1. Put your link bar right below your header and feature some of your main product categories. 
  2. Note that if your link bar is scrollable, only the visible items (without scrolling) are likely to have an increase in visits.
  3. Something to test is to then have a couple of rows in your link bar.