9.7K views · 241 reactions | How many line sizes can a fly rod handle? Can you underline or overline a fly rod? What will going up or down on a line size do to a fly rod, and how will it affect your casting? In this short video, Tom Rosenbauer shows what happens when you change line sizes, and gives you reasons for doing it—and when not to do it! | Orvis Fly Fishing | Facebook