When I talk about the larger diameter of US bass rods...

1 hour ago, WRB said:

Making visual side by side comparisons try adding accurate measured rod diameters, takes away the subjective guess work.

Most fishing rod blanks are rolled tapered tip to butt before adding rod handles and reel seats that are not expanded blanks to accommodate the components. 

Tom

Do you want precise measurements? I can provide them. Adding reel seats happens in two situations, for baitcasting rods. Reel seats adapted to thinner blanks, without inserts, who gives direct contact to the blank, for your fingers. And reel seats who need inserts, a cheaper solution, taking away the sensibility aspect.