I have a beautiful custom-made rod on a Sage Z-axis blank, 5 weight, 4 piece. I was roll-casting with it, perhaps 25 to 30 feet of line off the reel, 5 weight floating weight forward line, a size 10 or 12 light weight floating fly on the tippet. As I roll-cast forward, the distal (the smallest) piece of the rod snapped completely in two, about 2 inches above the ferrule.
The rod maker has a “You break it, I repair it” policy, and when I phoned him to tell him about it, he said he was convinced a lot of breakage of light weight rods was due to rough handling of the package containing the rod during shipping, i.e., the rod would be cracked or etc. during shipping and then the strain on the rod during fishing would complete the job.
Which got me to wondering (always weird, sometimes dangerous). In order to make the rod as light as possible, the rods are made with thinner walls, and if it is a fast rod, then would that make the rod more “brittle”? So would a fast light rod (like the Sage Z-axis or Orvis Helios tip flex, etc.) be more apt to snap than a heavier medium or medium flex rod? Or am I a million miles off the mark? What do you engineers out there think? Just wondering.
In my opinion, and that’s all it is, I would say yes. It doesn’t necessarily need to be a “fast” rod either. Take a look on a bass fishing forum sometime and see how many high dollar (light weight, thin wall) rods are snapped on the hook set…It’s ridiculous…
I have purchased 3 Z-axis rods in the past 3 years—a 5, 6, & 7 wt. No breakage problems thus far.
I think thinner walled, higher modules graphite rods will not take much side pressure or compression on the rods before damage is incurred. My unfortunate experience with this is with the higher wt. salty fly rods. A whack from an errant clouser minnow moving forward fast will more than do it.
I do not think they are brittle, just less tolerant of those side whacks with thinner walls.
I had a fast 5wt rod suddenly break but do recall having cast a heavy (for the rod weight) clouser minnow in a pinch and it coming back and hitting the rod … about where it was to break. Had a rod maker tell me this was no doubt what had weakened that rod section.
Tensil over Impact strength. I believe it was Al Campbell that stated that the biggest breaker of rods was the bead head fly! A sharp blow to the package during shipping could do the same thing.
The second time I fished a brand new, REALLY SLOW 8’0" 4wt Winston Retro FIBERGLASS rod; it snapped completely in half on a forward cast with a dry fly.
No beadheads, no Clousers, no hard casting, no graphite, no fast rod.
The factory couldn’t explain it either when I sent it in for the warranty repair.
Sometimes stuff just happens.
Ask Tom Kirkman @ http://rodbuilding.org. This topic would be right up his alley
My first fly rod was a Cortland CL Series 6 weight that was 9 foot length. The tip broke, while stringing the fly line through the loops, I do not know if it was me or them, so I repaired the fly rod with a new “Tip-Top” guide, after cleaning off the where the break happened (6-inches down former the tip-tip). Still fish the fly rod for Smallmouth Bass, and the the more sturdy tip section is holding up just fine. Actually I like the repaired fly rod (minus the 6-inches) more than before the accident (is anything really a accident or do thing put into motion resulting in the event?)
Things break, and you have to decide whether to repair it, or throw it out! ~Parnelli
I seriously doubt bouncing around in a tube during shipping is within an order of magnitude of the stress laid on a rod during casting. The rod, especially the lightest ones, lacks the inertia required to create that much stress, IMO.
I have broken a lot of rods and been there when a lot more of my rods were broken… Clousers, salmon flies, lead weights, and morons are the worst possible combination! 
art
All things being equal, your proposition is true. Any rodmaker will tell you this if they are being honest. This is actually where the no fault warranties came from in the first place. As rods became lighter and faster, tip sections began breaking just do to design implications under the same usage conditions. Many different rod mfgs and custom makers (who used to work for major mfgs) have told me this directly. The old IM6 and even first gen graphite blanks are the most durable. They are heavier, but they perform well and are rugged. This is why a lot of the instructional, beginner, and kids rods are made of this material even when introduced today. It isn’t that the material is any cheaper. It actually is all about the same price. And the lighter rods generally use less material in the same linear amount of blank. It’s actually a design feature meant to provide a benefit based on the intended use of that product.
With that being said, all things don’t have to be equal. If you learn to keep less pressure out of the tip section of a fast action rod you will be far less likely to break it. If you learn to “baby” the tip section when handling the rods, you will be far less likely to break them. And if makers would package them better, they wouldn’t get damaged in shipping. Sticking a tip in a tube and letting it bounce around during shipping is a good way to have high shrinkage costs as a mfg. or custom maker. But a lot of them do it!
Hmmmmm! Don’t see these kinds of problems with bamboo. To top that off, bamboo can be repaired. Might the material properties that is most often hyped by the marketing folks at the rod manufacturing places maby not be what it is cracked up to be?
fishbum
cool…just the right terminology
The break could be due to a loose ferrule. See #5 below.
http://americanangler.com/index.php?option=com_content&task=view&id=766&Itemid=0
I’ve got a Cabela’s seven-foot, two-weight Clear Creek outfit that I bought 4 or 5 years ago. I’ve caught a number of fish that people would consider far too large for a two weight rod. I regularly fish two beadheads or size #8 poppers and a dropper or John Barr’s hopper-copper-dropper combo. I sometimes have to really stress the rod for distance. The rod is still just fine after several years of heavy use and remains one of my favorite rods. I’ve never worried about having to replace it as the rod costs only $100. I don’t believe that most light rods are inherently more brittle than other heavier rods but they are, of course, easier to break because of their smaller diameter. BTW, I’m very sorry to hear about your problem. 8T 
8T, I don’t think he meant LOW line weight rated rods. I think he meant lightweight rods at any line weight recommendation. But you have a point: loading the rod properly in and of itself will not break it. The flex strength is very high. They simply will not stand up to impact.
The latest nano-resin technology called “Matrix Resin” from 3M makes fly rods both lighter and stronger. See the latest article in FFM.
There will be at least 4 new rod series out next year from St Croix, TFO, Hardy, and GLoomis using 3M Matrix Resin. The resin is true nano technology using SiO2 particles smaller than a nanometer (billionth of a meter) diameter to fill in the gaps between the graphite filaments.
The NRX is GLoomis’s rod series using this resin. St Croix will make their Legend Elite with it and they claim it is lighter and 30% stronger. Hardy will call their rod SYNTRIX and the TFO rods will be called the BVK…
3M Matrix Resin in carbon-fiber composites is a breakthrough.
http://www.tackletour.com/reviewicast10rodsstcroix.html
http://mountainriverjournal.wordpress.com/2010/10/07/new-tfo-nano-silica-_-ahead-of-the-rest/
Yep. The resins have improved significantly in the past few years thanks to advances petro/polymer nano-tech. That’s another part of what I was alluding to when I said “all other things being equal.” The new TFO BVK rods are way lighter than anything else TFO has ever put out, but they have most of the other same qualities as their Axiom series…only perhaps even better at the low and high end of the line. The 3wt is amazing!
A couple of Russian borne scientist just received a Pultizer prize for a new carbon material they were able to make that was only one molecule thick, but still stronger than steel. In a few years you will be able to buy a 3 oz. 9ft. 10 wt. for just under a $100K. If it ever breaks they will replace it for $50 plus shipping and handling.
I stand corrected. 8T
I think you mean the Nobel Prize. Pretty amazing to get a one atom thick material.