A few years ago I was fishing a new four weight bamboo fly rod. The DT4 line and leader I use on my fast action graphite rod wasn't working out. My loops were good but the leader would collapse, failing to roll the fly out there. Research on the bamboo forum led me to a statement that "the stiffness of the leader butt section should be equal to the stiffness of the fly line tip section". The butt section of my leader was way more stiff than the fly line, I assume killing the energy from my fly line. So I quickly built out a leader beginning with a 15 pound butt section. Problem solved. Energy from the fly line now transitions to the leader much better. Need to carry special leaders for bamboo, but not a big deal.