Ultralight camalot replacement interval

BD was beating around the bush with me on an email and won't give a real answer so here I am, hear me out. 

We are all told to replace our dyneema slings/soft goods every what-- 5-10 years? I know, it's debatable. But I think that most of us believe that we need to replace them even if they look good after a certain amount of time due to decreased strength of the dyneema fibers due to age even without use. 

So here is the real question: The STEMS of ultralight camalots are dyneema and are not replaceable-- so is the entire cam supposed to be thrown in the trash every 5-10 years? The cam can be reslung just like old camalots, but would you even want to if the non-replaceable dyneema stem is old and may have decreased strength? What are everyones thoughts on the lifespan of ultralight camalots due to the dyneema stem?

Sorry if already asked, I couldn't find an answer on here...

Pretty fucking shameful the manufacturer won't give you a lifespan number.

Sell them on MP, buy replacements during 30%+ off sales. Let dirtbags test their lifespan.

I was disgusted they even manufactured these because the people who actually need these for their climbs are so few. Being BD every Gumby with disposable income wants to buy a full rack of them “because they are lighter” without thinking long term. Having a dyneema stem is just wasteful, same as having plastic on the stem of the Z4s, like that isn’t going to break.

My opinion is that when it’s time to re-sling the ultralight cams it is time to retire them. 

Cherokee Nuneswrote:

Pretty fucking shameful the manufacturer won't give you a lifespan number.

That would be shameful, but it isn't true.   The lifespan of the UL cams is described in the instructions as "< 10 years".

I'll start worrying about this when I hear about one failing from age.  Until then, gonna send it.  The real issue with these cams is the trigger wires break and you gotta send them back to BD to fix.  I bought a double rack of them from .5 to 2, plus a 3 and a 4 when they first came out.  Nice weight loss for alpine climbing.  About a third of them have busted a trigger wire so far.  Happened with the old style C4s too, but way less often.    

Matt Nwrote:

Sell them on MP,

+1 for this. Not everyone is as conservative re. aging gear as you are.

Gawd, I spend more on the environment in one tank of gas to go climbing then a half dozen cams. 

Ben Mwrote:

Being BD every Gumby with disposable income wants to buy a full rack of them “because they are lighter...”

I resemble that remark!

Erroneous Publicuswrote:

I'll start worrying about this when I hear about one failing from age.  Until then, gonna send it.

Same. These things are plenty strong.

Retirement age for dyneema slings is probably not a good indicator for the lifespan of ultralight cams.  

The dyneema within an ultralight is encased in plastic which provides some protection from wear from friction, dirt, and light that alpine slings typically see.  My ultralights' dyneema still looks pristine, as far as I can see in the translucent thumb loop, and the appearance of dyneema is strongly correlated to strength in break tests.  

That said I definitely don't plan to use these past 10 years and plan to inspect them regularly after year 4. 

Double Jwrote:

Gawd, I spend more on the environment in one tank of gas to go climbing then a half dozen cams. 

Probably not. I guarantee the manufacture and delivery of those cams has a larger footprint than your tank of gas for the weekend. Over its lifetime, the BD ultralights have a larger footprint compared to a regular C4 mainly because of the shorter lifespan.

The stem of ultralight camalots is made of Dyneema, which is a brand name for UHMWPE yarn. UHMWPE yarns are also used in medical devices and body armour for soldiers, so America's National Institute of Standards has been studying their lifetime. Here's one such study where they used elevated temperatures to expedite the aging process: https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=916161

On page 47 they state:

Assuming that the
master curve presented in Fig. 2 is valid, one might predict that it
will take approximately 36 years for the tensile strength of this
UHMWPE yarn to fall by 30% at 43 C.

Note that this test only accounts for the impact of aging and does not consider the impacts of mechanical loading.

This sort of literature is likely what Black Diamond engineers used to come up with the (likely conservative) ten year lifespan estimate in the marketing materials. Only those engineers will know what math they did to justify those estimates. Perhaps they did the math based on a 10% derating with the worst case scenario for the cam storage conditions?

Perhaps we can get the how not to highline crew to pull test the stem on an ultralight cam in isolation so that we can see just how strong the stems are compared to the cam's stated MBS. That will give us some insight into just how conservative Black Diamond was when they listed these lifetime figures.

J Bwrote:

The stem of ultralight camalots is made of Dyneema, which is a brand name for UHMWPE yarn. UHMWPE yarns are also used in medical devices and body armour for soldiers, so NIST has been studying their lifetime. Here's one such study where they used elevated temperatures to expedite the aging process: https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=916161

On page 47 they state:

Note that this test only accounts for the impact of aging and does not consider the impacts of mechanical loading.

This sort of literature is likely what Black Diamond engineers used to come up with the relatively conservative ten year lifespan estimate. Only those engineers will know what math they did to justify those estimates. Perhaps they did the math based on a 10% derating?

Perhaps we can get the how not to highline crew to pull test the stem on an ultralight cam in isolation so that we can see just how strong the stems are compared to the cam's stated MBS. That will give us some insight into just how conservative Black Diamond was when they listed these lifetime figures.

I'd guess that the 10-year lifespan is just the conservative industry standard for soft goods. 

I'd also guess that the stems don't functionally limit the lifespan of the cams - the dyneema is protected by plastic which hopefully blocks UV and is hopefully overbuilt enough to withstand 30% loss of strength and still not be the weakest part of the cam. The risks of climbing on a 20 year old ultralight are probably dwarfed by the other risks you take climbing.

Ben Kraftwrote:

I'd guess that the 10-year lifespan is just the conservative industry standard for soft goods. 

I'd also guess that the stems don't functionally limit the lifespan of the cams - the dyneema is protected by plastic which hopefully blocks UV and is hopefully overbuilt enough to withstand 30% loss of strength and still not be the weakest part of the cam. The risks of climbing on a 20 year old ultralight are probably dwarfed by the other risks you take climbing.

Whether 10 years is the industry standard number or not, I'm sure the BD engineers used testing or modelling to estimate the true lifespan. I also don't think that its self-evident that the stem would be 30% overbuilt, considering that weight optimization was the entire point of the design change. 

I agree with your conclusion that this risk is minuscule in the grand scheme. The amount of force required to break a cams stem is far lower than the amount of force required to break a human body.

The cord that's inside the stem on ultralights looks just like amsteel blue, which is also made of dyneema. That's what they use for soft shackles for high lining,  pulling vehicles with a winch, in sailing, etc. It is stronger than steel cable of the same diameter. 

In the sailing world, they are exposed to constant sun and salt spray and get tensioned to hell. I would imagine they'll last a really long time. 

Will black diamond continue to re-sling them though? After the recommended retire date?

When they first came out.  Bd was saying 5 years.  I dont have a source just what I remember though.

Not Hobo Greg wrote:

That’s not exactly helpful, does that mean 9 years, 1 year, or what?

I believe it means that they recommend that you should retire your gear when it is heavily worn or damaged, or after 10 years, whichever comes first.

The instructions are the same as for the slings on both the normal C4s and the ULs.  There doesn’t  seem to be much confusion on how often BD recommends you resling normal C4s, why should this be any more confusing?

I personally replace my entire rack every 10 years

Ropes yearly

Peace of mind 

The whole issue of gear life is a can of worms. As a manufacturer I was involved when it became a requirement to give a lifespan and no sensible answer was ever produced and the manufacturers are left on their own, worse still there was no legal justification for any of the decision making and it all waits on a court decision.

To obtain EN/CE (and thus UIAA) for PPE it is nescessary to give an anticipated lifespan for the product BUT the sytem doesn't give a lower strength limit, the moment the product performance is lower than the requirements it is a fail. For most soft goods this is straight after it comes out of the packaging, for cams probably when it no longer achieves the cam rating itself.

Fundamentally it is all just a guess, there are no set criteria. At a major cam manufacturer I was involved with we decided over a few beers 10 years was the lifespan, science didn't come into it. The theory being the customer had had their moneys worth from what is effectively a disposable item. For my products (bolts) it's worse so we just give best case (forever) and worst case (one use).

alpinist 47wrote:

I personally replace my entire rack every 10 years

Ropes yearly

Peace of mind 

Can I have your 366 day old ropes?

alpinist 47wrote:

I personally replace my entire rack every 10 years

Ropes yearly

Peace of mind 

I hope you get A LOT of climbing done each and every year.