The first two rods that I made with carbon fiber ferrules were spigoted style ferrules and both of those rods did not hold up to strength tests I performed on them. Both of those rods broke. This style of carbon fiber ferrule is being used by several other builders. Yesterday I stepped out back from my house and caught about a 10 lb. carp and the rod did just fine. However, there is a mild set in the tip that I will get around to fixing someday.
Next week I am heading out to Last Chance ID and will give it a weeks worth of fishing out there. These ferrules weigh about 1/3 of what nickel silver ferrules weigh. The ferrules in the picture are 3 1/2" long. I think with further design I can even get them down shorter. The company that makes this tubing also does custom orders and right now I have on order material that is 50% CF - 50% fiberglass and special type of E-fiberglass.
The rod in the picture is an 8'5" 3/4 weight. In order to get the ferrules right the lower weight rods have to become of a parabolic nature. When I stepped out to cast this rod with a 3 weight line it was easy to cast 50'-60' into a mild breeze. I then put a 4 weight on and it took on a wonderful parabolic action that also allowed for long cast at a much easier pace. It also handled a 5 weight line as well, but I could drink a cup of coffee between back cast and forward cast. This rod weighs 3.25 oz.