Sun 27-Jan-13 03:15 PM | edited Sun 27-Jan-13 03:23 PM by nrothschild
The only reports of *shattered* CF tripod legs that I've heard of were the result of one of the following:
1) Slamming a car door or car trunk lid on the legs, which were left sticking out.
2) Running over a tripod with your car
In the case of a metal tripod, either of those would likely result in some bending of the legs. Once bent the leg presumably will not telescope and is "stuck" either collapsed or extended. Even a "dimple" in the tube would prevent a well built collar from working properly.
I have seen many reports over the years of bent and unusable alloy tripod legs. It is likely that it is more a problem with cheap lightweight alloy tripods with thin tube walls, and/or small upper leg diameter tripods. And that usually goes along with inexpensive.
My biggest concern is slamming a car door on the legs because I often keep the legs in the passenger side foot well, where it is easy for them to slip and hang out the door.
If CF can hold up to the rigors of a bicycle or F1 racing car, I would think it is up to the task of a hike along a trail
(edit: the following should be #3, and may even be the most common failure experience)
The biggest risk to a CF tripod, in real world use, is in snow or deep mud or perhaps loose sand, such as on a nice beach.
The problem is that when you put your gear on top, and then push down to stabilize the tripod in those types of loose and yielding surfaces, the legs are spread out un-naturally.
The result is either the tube cracking close to the upper metal fitting that bolts to the mount, or the mount itself. It is my pure speculation that the main reason for the new beefed up Gitzo Systematic mounts is to avoid this potential problem. I repeat, this is my speculation based on reports of failure in snow or perhaps deep mud.
The problem in deep snow is exacerbated by the cold temperatures, which tends to make metal and CF more brittle. It is also tough on the epoxy-like adhesive used to bond the CF upper leg tube to the metal mount fitting. Some of the failures were with the adhesive.
Eric Bowles has reported adhesive failure with his later Gitzos but I do not believe it to be very common. His was most likely a sample variation problem verses a fundamental problem with an improper adhesive, as was the case with the very early Gitzo CF MKI models.
A surprising number of those failures have been reported at Yellowstone NP, where it is apparently popular among the lunatic fringe to shoot in dead winter in temps down to -40F.
(just kidding about the lunatic fringe part)
Do a google on "gitzo failure yellowstone" or "gitzo failure" to broaden it a bit. And when you read those stories, keep in mind that most of those reports were with very early "MK1" versions of the G1325, G128, and similar first gen CF tripods.
Gitzo modified things with the MKII to lessen the problem but no matter what they do there is a fundamental problem with "over-spreading" the legs and apparently it is very easy to do in deep snow. So I think you will see reports on later models.
One of my biggest concerns with low priced CF tripods is the adhesive. In particular the adhesive used to glue the metal 3/8" stud fitting into CF center columns. Those failures are usually catastrophic although apparently not terribly common. It could be due to un-knowledgeable designers or just an attempt to save $0.50 per tripod to keep the price point low.
I have no reason to believe it is prevalent; just a concern of mine when I think about CF tripods built specifically for low price points.