The new large arbor spool is the result of a shift in thinking about the design of spinning reels. The large diameter offers several key advantages. You'll notice an increase in distance and ease of casting as the line leaves the spool in larger coils. Also the shallow large arbor spool helps to reduce line 'bedding into' itself. The surface area of the drag system is significantly increased and this improves the smoothness and power. We believe that this large arbor design will help to evolve and improve spinning reel design in the future.