Send us a suggestion!

Tech Tip: Question Shrinkage (ropes, canyoneering)

Discussion in 'Tech Tips and Gear' started by ratagonia, Jul 22, 2016.

  1. ratagonia

    ratagonia

    Messages:
    3,787
    Likes:
    4,354
    Location:
    Mount Carmel, Utah
    How much do ropes shrink as we use them?

    There is no standard test for this, so it becomes very hard to say. I think/guess/observe/no-really-it-is-a-guess about 5% in the first few trips, and not much past that. For my Imlay Canyon Gear ropes that are 100% polyester, sheath and core, thus perhaps more resistant to shrinkage than other ropes. But what is really true? Could we actually collect some data and find out?

    OK, let’s do that.

    June 22, 2016 – pulled a brand new 120′ Canyon Fire off the shelf. Actual length = 121 feet (1452 inches)

    June 21, 2016 – Imlay Sneak route with 3 ropes used randomly. 5 people. 27 rappels or so total, so used on approximately 9 rappel, mostly single strand. Wet.

    June 22, 2016 – Rope mostly dry. Measured length = 118 feet, 8 inches (1424 inches) ==> measured shrinkage = 1.93%

    Unfortunately, this rope sustained a core shot 20 feet from one end, and is now a 98 foot rope. (sigh)

    [​IMG]
    Coreshot



    Alas – next time for sure… I will work on it with a new rope, and probably track this shortened rope too.

    Tom
  2. 2065toyota

    2065toyota

    Messages:
    653
    Likes:
    696
    220' old - now 196'
    110' old - now 94'
    120' old - now 108'
    70' old - now 61'

    The last time I pulled my ropes amd measured them

    Sent from my SM-G900V using Tapatalk
    hank moon likes this.
  3. hank moon

    hank moon lovely ligatures

    Messages:
    1,225
    Likes:
    1,348
    What brand and model?



    Screenshot 2016-07-23 08.09.41.
  4. ratagonia

    ratagonia

    Messages:
    3,787
    Likes:
    4,354
    Location:
    Mount Carmel, Utah
    Kody - are the "original" lengths on those a measured length, or the nominal length stated by the seller?

    Tom
  5. Alias_Rice

    Alias_Rice

    Messages:
    156
    Likes:
    150
    Wouldn't it depend on how cold the pothole is? :happy:
    Rapterman and Yellow Dart like this.
  6. 2065toyota

    2065toyota

    Messages:
    653
    Likes:
    696
    That was the very first and second batch of ropes I ever bought. They were cut off spool at desert rat.

    The 220 and 110 were imlay old blue 9mm ropes

    The 120 and 70 were imlay 8.3mm.

    I don't use these anymore because of they have been used up, but I was really curious as to the shrinkage of them is why I measured. I would approximate at least 40 canyons of use on each of the ropes and the 9mm to be around 10 years old

    Sent from my SM-G900V using Tapatalk
  7. 2065toyota

    2065toyota

    Messages:
    653
    Likes:
    696
    My current ropes I wish I would have measured them before I started using them. I have a mixture of bagged ropes and spool cut ropes so it would have been nice to have current data on the newer ropes, but I won't have accurate info on those

    Sent from my SM-G900V using Tapatalk
  8. ratagonia

    ratagonia

    Messages:
    3,787
    Likes:
    4,354
    Location:
    Mount Carmel, Utah
    Also please note that ropes cut at a store are not always accurate in length. The roller gauges at many stores are not necessarily accurate to the degree many people expect, and may not work well with the particular rope being measured.

    Tom
    Rapterman and 2065toyota like this.
  9. 2065toyota

    2065toyota

    Messages:
    653
    Likes:
    696
    Bottom line. Measure your ropes after you use them and get them wet so you know how long they really are
    Rapterman likes this.
  10. ratagonia

    ratagonia

    Messages:
    3,787
    Likes:
    4,354
    Location:
    Mount Carmel, Utah
    Do you think being wet changes their length? Guess I could check that.

    Tom
  11. 2065toyota

    2065toyota

    Messages:
    653
    Likes:
    696
    I was more just referring to use them in a wet canyon and after they dry out measure them, the wetness during measuring could cause some shrinking I guess, but I would think that amount would stretch back out during use.

    Being 5' short on a rap isn't too big a deal, but add 5' more feet to that and it could be bad
  12. Yellow Dart

    Yellow Dart It's only hubris if I fail.

    Messages:
    198
    Likes:
    213
    Location:
    La Verkin
    As bad as sliding around in the Subway? :happy:
    2065toyota likes this.
  13. Kuenn

    Kuenn

    Messages:
    1,294
    Likes:
    1,311
    I have observed over the years that larger diameter rope have less shrinkage by ratio compared to equal lengths of smaller diameter rope counterparts (experience has been primarily with nylon). I submit that shrinkage will eventually level off on the front end of the rope's use, meaning it's not something that is a constant with each wet/dry cycle (that's the short answer).

    I still have a 100' length of 11mm Bluewater that was purchased in 1972... and it didn't start out as a 300 footer. (well, actually it did but I cut it after purchase).

    Another observation with long rope (>300'), is the shrinkage effect "appears" to be even less than that of the same rope at shorter lengths. Possible reasons could be due to wet/dry cycles being much less frequent/dramatic, or measurement challenges, or even the stretch aspect getting reset from the "bedding in" effect (see bedding in reference in this article from Rock and Ice).

    An added reason to consider when purchasing rope (not just $/ft)... some suppliers add a few bonus feet to your purchase. Thankee to them!
    Last edited: Jul 27, 2016
    2065toyota likes this.
  14. hobo_climber

    hobo_climber

    Messages:
    24
    Likes:
    23
    Location:
    New Zealand
    You guys are using the wrong ropes!! I made the switch to Kordas a couple of years ago, pre shrunk, hard wearing, soft handling... beautiful!

    Bonded core and sheath in their canyoning range, and the Titan tech in their Spelo range make these rope the toughest i've ever come across.

    Zero shrinkage experienced :thumbsup:

    http://www.sacidkordas.com/en/sport/barranquismo/dana-9
  15. Kuenn

    Kuenn

    Messages:
    1,294
    Likes:
    1,311
    Don't want to hijack this thread... so quick response.

    @hobo_climber Although unicore technology has its appeal, with reduced rope shrinkage and sheath slippage (and some pretty wild colors), but to quote Mr. Pope, "Be not the first by whom the new are tried, Nor yet the last to lay the old aside." I'm still on the left side of that adage... and will probably be there for a while. It's hard to leave a good thing, even considering the minor glitches.
    2065toyota likes this.
  16. ratagonia

    ratagonia

    Messages:
    3,787
    Likes:
    4,354
    Location:
    Mount Carmel, Utah
    I have started up this project again, given the chance with some friends going through Imlay. Which they did. Written up on The Rave, however, it is not much of a writeup, so I copy it here ---

    How much do ropes shrink as we use them?

    There is no standard test for this, so it becomes very hard to say. I think/guess/observe/no-really-it-is-a-guess about 5% in the first few trips, and not much past that. For my Imlay Canyon Gear ropes that are 100% polyester, sheath and core, thus perhaps more resistant to shrinkage than other ropes. But what is really true? Could we actually collect some data and find out?

    I will list and update the data collected here, with generally the latest data on top.

    Rope #2 – Imlay Canyon Fire Rope, 120 foot nominal length. Put in service 6/2/2017
    122 feet 0 inches – original carefully measured length.
    6/3/2017 – Full Imlay with 4 people/4 ropes, this being one of them. Wet and dry.
    118 feet 10 inches – first canyon loss of 2.6 %

    Rope #1 – Imlay Canyon Fire Rope, 120 foot nominal length, Put in service 6/20/2016
    121 feet 0 inches – original carefully measured length
    6/21/2016 – Imlay Sneak route w 3 ropes, 5 people. Wet and dry.
    118 feet 8 inches – first canyon loss of 1.9 %.

    unfortunately, Rope #1 was coreshot in the canyon, and reduced in length, and I stopped using it to measure shrinkage…
    Last edited: Jun 6, 2017
  17. Bootboy

    Bootboy Atwood Gear

    Messages:
    1,525
    Likes:
    1,702
    Location:
    Utah
    I have a brand new 120' nominal canyon fire. I will accurately measure it before putting into service and see what happens over the course of the fall season


    Sent from my iPhone using Tapatalk
    dakotabelliston likes this.
  18. ratagonia

    ratagonia

    Messages:
    3,787
    Likes:
    4,354
    Location:
    Mount Carmel, Utah
    That would be great! Got that 100 foot tape measure?

    Tom
  19. Yellow Dart

    Yellow Dart It's only hubris if I fail.

    Messages:
    198
    Likes:
    213
    Location:
    La Verkin
    Will be doing the same with a spool of new canyonfire. When I used my mechanical measurer, it came to 601'. So a couple 300's. I'll letcha know after a while.
  20. ratagonia

    ratagonia

    Messages:
    3,787
    Likes:
    4,354
    Location:
    Mount Carmel, Utah
    One of those rope-pull-through type measurers?

    For percentage shrinkage they are OK. But for actual length - not so much. Calibrate it. I know YOU have a 100 foot tape measure.

    Tom
Similar Threads: Shrinkage (ropes
Forum Title Date
Archives - Yahoo Canyons Group Rope marking and shrinkage. May 17, 2010
Archives - Yahoo Canyons Group Gear~Rope Shrinkage Jun 24, 2007
Archives - Yahoo Canyons Group Shrinkage Dec 8, 2003
Trip Reports Boundary - June 12, 2013 (ROPES FOUND) Jun 13, 2013