I do not agree that breaks in the lower sections of the rod are not or cannot be caused by using a tippet that is too strong. I have broken one rod in the lower sections, breaking #8 and #9 in a 10 section rod (section counts start from the tip as #1). The break was right at the junction between #8 and #9, but was not a clean break. I was trying to stop a fish that was much too large for the rod (the largest trout I've ever hooked) and the bend in the rod was concentrated in the lower sections. I am sure that had the tippet been weaker, it would have broken before the rod did. I was using a Tectan spinning line for tippet that had a breaking strength of a bit over 6#. That was very early in my fixed line fishing and I didn't have any sense of what a rod could take.
I have broken one rod that was a clean break and occurred exactly where #3 came out of #4. I don't think tippet strength was an issue. I was surprised by what I thought was a fish and struck too hard on what turned out to be a log. I think the quick, sharp strike focused the bend right at the spot where a junction created a harder spot, kind of like the guy's finger creating a hard spot caused the fly rods to break in the video. I have what is left of the broken part, and have tried tdo break it. I am sure I can break it, but I was surprised at how much strain I have put on it without breaking it. Similarly, one of the rods I lent out very early on to get a user's perspective came back with a broken tip. I then tried to break what was left and was very surprised at how much strain I could put on the tip without breaking it.
Daiwa tenkara rods do have reinforcements at the junctions. The walls of the tubes are thicker on the butt ends of each segment so there is additional material where a section comes out of the next larger one - which is right where the one clean break occurred on the rod above. Daiwa also has what it calls a "V" joint, which makes the joint less of a hard spot.
Last edited by CM_Stewart; 11-05-2013 at 06:44 PM.