TECHNICAL FORUMS > Equipment
Tutor XG shrinkage
Yesterday was somewhat chastened to find that my doubled 30m rope did not actually reach the ledge on the big pitch in Swinsto, in contrast to many previous trips. Neither did the other one. I assumed I had made a cock of things, age probably.
Both came off a recent 200m drum that measured at 205m. I have always cut new rope with a 10% allowance (literally measuring out 11m and calling it 10), which has always worked fine. I have just remeasured all the rope with a survey tape to find the error, and the grand total is now 172m. That’s a lot of shrinkage. Even assuming it was 200m that is 14%, but it is 16% measured. So “30m” becomes 27m.
I like the rope, but that seems slightly odd.
Did you wash the rope before cutting?
Pre-washing allows the rope to shrink already 10-15%. When you cut the pre-washed rope the shrinkage will be less afterwards, but there still will be some shrinkage.
Like most people I soak my ropes when I get them, and they sure shed a lot of detergent. Aside from pre-shrinkage it's the main reason why I do it, the first descent on a brand new skinny rope would otherwise be terrifyingly fast.
I find this initial process causes ~10% shrinkage dependant on the rope, I then measure these ropes and give them an additional 10%. (i.e. a washed 33m rope gets labelled 30m, etc.). Having re-measured ropes on occasion it seems to me that the first wash causes most of the shrinkage, with not that much happening afterwards (5% on my 4yr old CC unicore rope).
The only thing I have been doing differently recently is putting them in the washing machine after cutting because it is less work. Maybe that gives them the hurry up. 15% seems a lot for unused rope. It will be 20% when older.
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