Decrease in elongation of dynamic ropes over time?

Do dynamic ropes lose a bit of elongation over time (either through wear from use or just degradation over time)? This seems anecdotally true, and the "elongation at first fall" rating is rather suggestive. I haven't been able to find anything published on this though.

When used heavily, yes they will lose elongation over time. Think of the rope like a rubber band. If you keep stretching it eventually the rubber band will lose the elasticity that it had when you pulled it from the package. I would only worry about losing elongation in your rope if you plan to beat the hell out of it and take massive falls continuously over long periods of time without changing which end you are falling on.

Two separate issues.

“Elongation are first fall”— because dynamic rope stretches, and then takes time to recover. And if you keep taking the exact same fall on the rope within short time window, the subsequent falls will have different force/elongation measurements. The rope manufacturers report the info for the first fall, to keep things consistent.
In practical terms, if you are spurt climbing and taking repeated fall at the crux, the subsequent falls will be a bit stiffer, but you are unlikely to notice it, unless the falls you are taking are particularly bad. But if you are taking repeated redpoint attempts, switching the ends of the rope between tries is a good idea, both in terms of wear on the rope, and in terms of letting the rope recover. 

This kind of elasticity loss is reversible. After the rope rests for a day your “elongation at the first fall” would he basically the same as the brand-new rope.

However, over time, the nylon does age, and older rope will likely feel stiffer, even if nobody was falling on it. 

In order to find the edge of exertion, and reach peak performance without fear, {~)To be able to have control, focus & the power to climb better at harder grades (& longer run-outs) one needs to hone the ability to suspend one's 'disbelief' (or belief that YGD)
The  "it's not scary" mantra, (or a favorite song or lyric)  deployed when facing certain death,  works better if you can get past doubting the security of your gear,
Yer Gonna Die , but not from nylon failure, (Planned Obselecance & Dyneema, sewn new-age 'Dentil Floss'  is a whole other can of worms)

There is a thorough scientific study done by Black Diamond: qc Lab Old Vs. New Gear Testing 

 (edit: maybe more relevant, what Rock&Ice say.  , There are a few good studies See also: J Titt Here On MP)
By gaining knowledge, giving a racing mind something to grasp, info that re-enforces confidence, reduces fear & doubt, helps one focus on the climbing)

 When treated with the proper care & respect due a "Life-Line"(&-pre- 2002?) modern ropes lose very little elasticity & no strength over decades of use (The type of moderate"work" that climbing forces exert on modern rope(s) is well documented to be well with-in "safe" tolerances.  

 ~ the only thing you really need to watch out for
& even then in a pinch a wrap or 2 of Tenacious Tape or "Gorilla" brand tape  will hold up for a few days on the wall...

mattm wrote:

I’m a bit skeptical about this. 50 pitches is like one month of sport climbing. This means that a typical rope, after about 4 months of weekend sport climbing, would basically have the energy absorption of a steel cable. Considering that I generally retire a rope after two to four years, I do know that is not the case. 

Suburban Roadside wrote: There is a thorough scientific study done by Black Diamond . . . .
 When treated with the proper care & respect due a "Life-Line"(&-pre- 2002?) modern ropes lose very little elasticity & no strength over decades of use (The type of moderate"work" that climbing forces exert on modern rope(s) is well documented to be well with-in "safe" tolerances.  

Could I get a link for this please?

https://www.blackdiamondequipment.com/en_US/qc-lab-do-ropes-need-to-rest-between-falls.html

This article shows significant increase in forces after falls that is mostly recovered within 24 hours. 

This might interest you, it pertains to lowering cycles vs rope degradation:
http://personal.strath.ac.uk/andrew.mclaren/Turin2002/CD%20congresso/Safety%20loss%20.pdf

There's also https://www.theuiaa.org/documents/safety/Conference_on_nylon_and_ropes.pdf
& https://www.theuiaa.org/documents/safety/About_Ageing_of_Climbing_Ropes.pdf

r m wrote: 
 This_ _ _ _ _ 1st link no workee________ might interest you, it pertains to lowering cycles vs rope degradation:
http://personal.strath.ac.uk/andrew.mclaren/Turin2002/CD%20congresso/Safety%20loss%20.pdf

&
how does anything about rope failing by cutting over a edge help?

 the,  'stupid-bad-luck' of the German military, is literally a one off\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\Anything that re-enforces confidence, reduces fear & doubt, helps one focus on the climbing

  ropes in contact with sharp limestone edges - prone to cutting ? Who would have thunk it!
so  does this help?
 https://www.theuiaa.org/documents/safety/Conference_on_nylon_and_ropes.pdf
& https://www.theuiaa.org/documents/safety/About_Ageing_of_Climbing_Ropes.pdf

Fair point, I was thinking "energy absorption", which is related non-trivially to elongation. But is a slightly different question!

My mistake!

But hey I did say might ;)

[Under chrome the first link works if you scroll in the top part of the page. I don't know why it's broken in that way.]

[Edit: Internal OT reflection:

I haven't been sleeping well and this morning I found my spelling and grammar were abnormally bad. The decay of self is something I witness from time to time! Not entirely surprising I should also fail at reading. Such is life.]

John Ryan wrote: https://www.blackdiamondequipment.com/en_US/qc-lab-do-ropes-need-to-rest-between-falls.html

This article shows significant increase in forces after falls that is mostly recovered within 24 hours. 

This is true. A rope should be allowed to rest after catching a hard fall. However, the above graphic from “weigh my rack” suggests that just climbing and lowering on about 200 pitches will cause a rope to lose around 90% of its energy absorption qualities, no falls needed. That, I disagree with. 

the schmuck wrote:

This is true. A rope should be allowed to rest after catching a hard fall. However, the above graphic from “weigh my rack” suggests that just climbing and lowering on about 200 pitches will cause a rope to lose around 90% of its energy absorption qualities, no falls needed. 

"Weigh My Rack" reused graph from https://www.theuiaa.org/documents/safety/About_Ageing_of_Climbing_Ropes.pdf 
X-axis is meters climbed and rapped/lowered, goes to 25000m. Estimating 30m per pitch, that is over 800 pitches. Of course, it would be interesting to know how the energy absorption capacity was measured.