Not just harness risers but hang straps which tend to be much lighter material and subject to lots of rubbing motion from contact with the caribiner. I doubt very many biners get opened and closed more than 10,000 times in their lives. I would hazard a guess that is not subjected to frequent exposure to sand that a biner would be good for a million cycles. But for $35 to $45, why be cheap about it? Did you know that the sail on a topless glider cost nearly $5,000 and has a useful life of less than 500 hours? That's an amortization rate of $10/hour for just the sail. For me the true cost of hang gliding is ~$60/hour over the long run. $40-45 dollars of that per hour cost is related to transportation.greblo wrote:....Perhaps an even more pertinent discussion is when to replace your harness mains since they deteriorate much more easily than a steel caribiner.
It's easy to be penny-wise and pound foolish in this sport and that's exactly what pilots typically do. Steve Pearson gave me the classic example of this when he introduced the Litestream and Slipstream control bar legs (downtubes). These were engineered to break before the pilots' arms fractured. Pilots were soon complaining that they were having to shell out $65 a pop and were soon switching back to Attack downtubes which were over-built. The rate of spiral fractures of pilot forearms soon rose in proportion to the sale to Attack downtubes.
As far as breaking strength of connection components goes, I would hazard a guess that any force in excess of 2,000# against the harness risers will result in either a dead or paralyzed pilot. Just ask the late Adam Parer or the living Bill Soderquist about their respective deployments after free-fall. Adam's was at 120mph with a QS-330 and Bill's was more like 50-60mph with a LARA 250. Both pilots were badly injured by those opening shocks which took place with each pilot in a semi-upright posture.
Had they been flying cocoon harnesses like me the shocks would have probably snapped their necks. Trust me that I know personally how little force it takes to fracture a neck in the face-down posture.
George's incident had nothing to do with the caribiner. The slider rod on the back plate of his harness was torn out during an accidental 6G pull-up. The story is on the forum somewhere and here: http://ozreport.com/pub/rotorfailure.shtml
Adam Parer: http://adam-parer.blogspot.com/2009/11/ ... death.html
Bill Soderquist: http://www.freeflightent.com/hang-glidi ... rvival.php