Yes, I am infamous for having very bad ropes. Comes from using ropes from the Black Diamond Returns Department (free!!) and just not really caring.
Core shots are where the sheath is worn away so that the core shows. The first stage is the Core Gobi, where a couple strands on the sheath are worn through. With repeated rappelling, a core gobi tends to grow around the rope until it goes all the way around and becomes a full Core Shot.
What’s a few core shots between friends?
I’ve put a few core gobis on the test machine. One thing about a kern-mantle rope is that the core and the sheath act pretty much independently in straight pull. So even with a full core shot, the rope still reaches full strength for that rope (your mileage may vary), after breaking whatever is left of the sheath at a low stress.
But real core shots can be very dangerous in the field. Rappelling over one and pulling the core apart is very stimulating, as you slide a couple feet with the sheath sliding on the core. The next person rappelling has the difficult task of rappelling onto the core, then getting back onto the messed up sheath below that. The sheath bunch can easily get jammed when trying to pull the rope. It can also get jammed in your rappel device when you try to get past it.
So, what’s the point? Strength is not usually the issue, but usability definitely is. Core Gobis will grow into Core Shots. People canyoning with me often prefer using their own ropes.
Tom
— In Yahoo Canyons Group, “Teuns Kok”
Summer is heating up in SA, which mean canyoning season! Yesterday I > spent very many Rand’s on new rope – 110 meters of 9 mm Rocca static to > be cut in half. (Toss and go is still the standard for most > recreational canyoning down here!) Wonderfull feeling to run that rope > through my hands – all soft and shiny.
Of my old ropes (Beal 9 mm static) the one has a badly damaged sheath > down to the core and is definately retired. Middle point of the rope > damaged! The other one (also Beal 9 mm static) has become very stiff > and fuzzy.
So, I am wondering how often does people change their ropes, with > reference to recreational canyoneers? And do they stick to the same > make or are they willing to try something new?
Teuns