Difference in 60m rope lengths from different manufacturers

I recently got a 9.2 from Black Diamond and it has almost 100 pitches on it. I've noticed it has seemed a bit short on several 30m pitches/rappels, and so I compared it to a 60m petzl volta. The Petzl is about 3m longer than the Black Diamond. 

Has anyone else noticed a rope from Black Diamond being excessively short? I know some variance from manufacturer to manufacturer is normal, but this seems like a bit much. 

Not sure, but I doubt BD shorted you. However some manufacturers intentionally add a few meters so that as ropes shrink as they age you won’t be “short roped”. It might just be that the Petzl you are comparing has some extra. I have a pair of 1/2 ropes from Edelrid, one is 4 meters longer than the other, but I believe the shorter one is still 60m. 

That does seem like a bit much. I think the UIAA allows for +/-1 meter, maybe 2 meters; insofar as I'm remembering that correctly, which I'm almost certainly not, it could theoretically be possible for two nominal 60m ropes to have up to a 4m difference with no extreme failures of quality control on the part of either manufacturer. But I'd be surprised by that kind of difference, and probably also unhappy.

They should never be too short. If your rope is too short contact the manufacturer and have them send you the new rope they owe you. 

They are often a little long, no harm in that unless you are counting ounces. 

Pat Light wrote:

That does seem like a bit much. I think the UIAA allows for +/-1 meter, maybe 2 meters; insofar as I'm remembering that correctly, which I'm almost certainly not, it could theoretically be possible for two nominal 60m ropes to have up to a 4m difference with no extreme failures of quality control on the part of either manufacturer. But I'd be surprised by that kind of difference, and probably also unhappy.

The length must be "equal to or greater than the published length of the rope." https://www.theuiaa.org/documents/safety-standards/101_UIAA_Ropes_V9_2019.pdf

My understanding was that many manufacturers cut their ropes long.

TJ Brumme wrote:

I recently got a 9.2 from Black Diamond and it has almost 100 pitches on it. I've noticed it has seemed a bit short on several 30m pitches/rappels, and so I compared it to a 60m petzl volta. The Petzl is about 3m longer than the Black Diamond. 

Has anyone else noticed a rope from Black Diamond being excessively short? I know some variance from manufacturer to manufacturer is normal, but this seems like a bit much. 

Isn’t your reasoning a bit off? You compared two ropes but you don’t know the exact length of either. How do you know that the Petzl rope is not overly long?

Mark Hudon wrote:

Isn’t your reasoning a bit off? You compared two ropes but you don’t know the exact length of either. How do you know that the Petzl rope is not overly long?

 A man with one watch knows what time it is, and a man with two watches could never be sure.

Allen Sanderson wrote:

 A man with one watch knows what time it is, and a man with two watches could never be sure.

If he gets two watches, I want two

Mark Hudon wrote:

Isn’t your reasoning a bit off? You compared two ropes but you don’t know the exact length of either. How do you know that the Petzl rope is not overly long?

It sounds like the OP is concerned because he was coming up short on raps know to be 30m (or less). It seems normal to do a quick check against another 60m for a non-definitive reference. To make a warranty/defective claim with BD the OP will need to measure the rope more precisely. Outdoor shops that sell cord by the foot/meter usually have a measuring wheel, that's probably the easiest way to get a more definitive measurement. 

Scott D wrote:

It sounds like the OP is concerned because he was coming up short on raps know to be 30m (or less). It seems normal to do a quick check against another 60m for a non-definitive reference. To make a warranty/defective claim with BD the OP will need to measure the rope more precisely. Outdoor shops that sell cord by the foot/meter usually have a measuring wheel, that's probably the easiest way to get a more definitive measurement. 

Exactly this. Haven’t had time/patience yet to measure the ropes by hand, so the quick comparison with the petzl had to suffice. Possible that the BD is 60m and the petzl is 63m, but unlikely. Once I get around to measuring I’ll update here.

TJ Brumme wrote:

Exactly this. Haven’t had time/patience yet to measure the ropes by hand, so the quick comparison with the petzl had to suffice.

Because I sew, I have a 5 foot soft measuring tape in my sewing kit. the first thing I do when I get a new rope is flake it three times, then hand measure it -  it only takes 2 minutes. I’ve never had one come up short.  

Could some of it be shrinkage from use?

The “30 meters” rap/pitch is itself an estimate.
Wouldn’t it be more productive to have some facts before posting on a forum?

My previous 70m rope (edelrid) was just about 2 cm over 75m (not stretched).  So certainly possible his petzl is 3m over. (Doesn't edelrid make petzl ropes or did at one time?)

Mark Hudon wrote:

The “30 meters” rap/pitch is itself an estimate.
Wouldn’t it be more productive to have some facts before posting on a forum?

This is Mtn Project. We don't need no stinking facts. 

A dude I hire to guide me loved Mammut ropes, but was convinced they cut the rope at 60m exactly, because they never reached the ground on 30m raps except with rope stretch. I compared my Sterling to the Mammut, it was about 10 feet longer. I bought them both in 2017, and used neither very much. 

BD ropes are made by either Roca or Lanex, depending on year. 

Buck Rio wrote:

A dude I hire to guide me loved Mammut ropes, but was convinced they cut the rope at 60m exactly, because they never reached the ground on 30m raps except with rope stretch. I compared my Sterling to the Mammut, it was about 10 feet longer. I bought them both in 2017, and used neither very much. 

BD ropes are made by either Roca or Lanex, depending on year. 

We had repeated bad experiences with length of a Mammut rope. It was over 10 years ago now, but at the time was their most expensive rope.
Have not tried them since.  

My Mammut and Edelrid ropes are pretty close to the same length, my fiends petzl rope is close to 3-4 meters longer.

This non-uniformity is a problem when putting in rap anchors.  I climb on a 70 meter  rope (mammut or edelrid) and have marked 5 meters from each end so I know how far a 60 meter rope will reach.  If I had rope with a few extra meters I would likely be putting in anchors too far for some ropes. :(.  Of course I am shooting for ledges and comfortable rappel locations and try to to push the length as much as possible so it does not come up too often.

Of the ~ten 60m ropes I've come in close contact with, 2 were 64+ meters long.

TJ Brumme wrote:

I recently got a 9.2 from Black Diamond and it has almost 100 pitches on it. I've noticed it has seemed a bit short on several 30m pitches/rappels, and so I compared it to a 60m petzl volta. The Petzl is about 3m longer than the Black Diamond. 

Has anyone else noticed a rope from Black Diamond being excessively short? I know some variance from manufacturer to manufacturer is normal, but this seems like a bit much. 

one way to determine is a wheel... another way is going to the local all weather track, starting at the 100m start line, gently lay it out. flip it and keep going to the finish line, fold the remaining 20m (that extends past the finish line) back on itself, then the 60m-80m portion again (so three sections together). They should all meet within 0.5m. If short, you may have a more valid complaint. Until this is done, sounds like you have as much certainty as the rest of us... very little. good luck.

Christian Hesch wrote:

gently lay it out

The standard length test involves a ~30m catenary with 1m sag, which corresponds to 7-10kg tension.  This is relevant to real use in that a rope hanging under its own weight shortly after being subjected to a rappel load will have a very similar length to what the standard test shows.  Laid gently, a dynamic rope will measure ~5% shorter.