Are the high modulus graphite rods brittle and do they break easily?
I won’t argue the fact that today’s high modulus graphite rods are not as durable as rods made from lower modulus fibers of a few years ago. But the decrease in durability is not the result of “brittleness” as might be suggested. The first graphite used for the production of fishing rods had a much higher modulus, although a much lower tensile-strength, than fiberglass. Still, its strain-rate was strong enough to provide adequate durability and its higher modulus made it extremely sensitive. In those early days of graphite rod making, it was hard to climb the ladder to even higher modulus graphites because as the modulus increased, the strain-rate decreased. Put simply, the stiffer they got, the more brittle they got, just as you suggest. But a graphite fiber known as IM6 changed all this. With IM6, not only did you have a higher modulus, but a higher strain-rate as well. For the first time it was possible to produce a lighter, more sensitive rod without losing durability due to brittl
