The following article is courtesy of Black Diamond Equipment.
Here at BD we are all a bunch of tinkerers. We're constantly tweaking our gear or cobbling together prototypes, trying to make them lighter and perform
better.We fiddle with gear, test it in the lab and take it out into the field.Therefore, when people want to customize and modify our products, we
But there is a reason that we have a blurb in all of our instructions for use stating, "do not modify this product in any way." It's not that we're trying
to limit creativity. It's because we've gone through painstaking efforts to ensure that our products meet all necessary strength and certification
requirements, and behave how they are intended. We need to consider typical use, misuse, and abuse. We need to consider ultimate strength, durability,
manufacturability, ratings and certifications. The end result is a product that we're psyched about and meets all external and, just as importantly,
internal requirements we put on it.
When people modify their gear, they may unwittingly be changing a critical design or strength feature.
When I'm out climbing I see some of the mods that people have done, and I cringe. I also get lots of emails asking if I recommend a particular tweak, change
or modification to a product. A few examples and my immediate thoughts:
- Drilling holes in ice tools: People do this to add leashes, add makeshift pommels, or allow better use as a dead man. Our ice tool shafts
are burly—they pass all CE requirements. But by drilling a hole, specifically in a high stress area, you can significantly decrease the ultimate
breaking strength and/or fatigue life. Yes, I've seen drilled ice tools break at a hole someone had drilled.
- Drilling holes in belay devices to make them lighter: Do you really want to start jeopardizing the integrity of one of the most critical components
in the belay chain? Many, like the ATC-Guide and ATC-XP, already have the sides cut out for those weight conscious folks.
- Adding an additional belay loop to your harness: Belay loops are burly strong. You don't need a belay-loop backup—it just adds more clutter and
opportunity to mis-clip, and have weird loading on your belay loop. Check out this previous QC Lab post here: Worn Belay Loops and Retiring a Harness. Sure,
some harnesses, usually big wall harnesses (like our Big Gun), come with two belay loops. That's so you can keep the excessive amount of gear you're
using nice and organized—NOT for you to belay using two belay loops.
- Adding additional gear loops to your harness: Sewing into a structural component of your harness is not recommended. If you want more gear loops, get
a different harness.
- Modifying one manufacturer's picks to fit in another's ice tools: The pick/tool interface is pretty critical. Tools are tested as a system and using
a pick that isn't designed for that tool compromises the entire system.
- Using aluminum rear rails to save weight on steel crampons: The risk here is even though it's a rear crampon rail, the aluminum down points aren't
nearly as durable as steel and will quickly wear to being too dull to do you much good. Weight savings always costs something, and in this case
These are just a few random examples among many we've encountered, but we decided to choose three instances of modification that we've seen come up lately
and test them here in the lab. Many modifications fall under the category of "not a good idea," but the examples below are ones we think might actually
be legitimately dangerous in situations of consequence.
This one has been covered before but it's worth revisiting. Re-slinging Camalots with open loop or extendable slings—one of our most frequent questions.
Could we replace our slings with either an open-loop sling/runner or an extendable sling? Sure. But we don't, and we don't recommend it. Open loop
slings, narrower spectra slings or extendable sling configurations result in a higher likelihood of tweaking your thumb loop under normal falls, and
in the worst case, cutting the slings at lower than originally intended loads.
Older-style Camalots had an open-loop sling; C4s, C3s and X4s have a sewn sling that is double thick where it contacts the wire cable of the cam. This
is for two reasons:
1) Ultimate Strength
These slings are designed to attain the strength ratings we desired. During loading, the cable thumb loop pinches down, and in-effect eventually cuts through
a single thick sling at between 9kN-10kN. The double thick sling distributes the load, and allows the sling to meet higher load—up to 14kN.
2) Tweaked thumb loops
During a loading situation, the single layer of webbing isn't firm enough, and the thumb loop pinches down resulting in a slightly kinked cable. The double-thick
sling alleviates this.
Lots of people seem to think an extendable sling on a cam is a good idea. There are three reasons why we don't use extendable slings on our cams and why
we don't recommend replacing BD cam slings with extendable slings:
1) Extendable slings are bulky and just make a mess of your rack. Plus, if you look at a typical extendable cam sling vs. a non-extendable, it's only
about 1 carabiner height longer. Use a shoulder length sling when you want to extend the sling and avoid cams walking and/or rope drag.
2) When used in extended mode, they result in lower strength values than standard slings
3) Again, there is a high possibility of tweaking the cable in the event of a fall
USING OTHER MANUFACTURERS' BAILS ON YOUR CRAMPONS
Not all manufacturers use the same diameter of toe and heel bail wire, flats on the ends of the wire, or holes which they fit into on the front and rear
rails. Use a smaller wire with the larger hole, and the crampon won't meet the CE and UIAA strength-of-bail-attachment requirement of 1kN. More importantly,
you risk the possibility of the bail popping out mid-pitch.
This test involves pulling or prying the bail wires away from the crampon rail. Check out the following link to see how we set up the test: http://www.theuiaa.org/safety_standards.php
[Note: test performed on BD rails. EN893 requirement (section 4.3.3 transverse strength bails) = 1000N (224.8lbf) proof load.]
The above data shows that using mix-matched bail wires and crampon rails can result in it being pretty darn easy for the bails to pop out. Not ideal.
MODIFYING YOUR ICE TOOL TETHER SYSTEM
Word on the street is that some folks believe ice tool tethers are capable of arresting a fall. News flash: they're not, and that's not what they're for.
It seems that I've already been through this, however, I've still had a few people ask if
they replaced the attachment points with "full-strength" biners, would that cut it? No.
I've even caught wind of some creative folks out there wanting to incorporate a "Screamer" into their tether system, so it reduces the load, acting more
like a via feratta. Still not a good idea. Don't believe me? A few of the crew headed down to the drop tower to demonstrate. We connected a spinner
leash to two ice tools and rigged up a Screamer to the mass in our drop tower and did a few realistic drops—representing either one or both arms
of the tether taking the load should your feet pop.
Therefore this showed that even with an energy absorption system in the mix, it doesn't matter. The load generated is still high enough to break the tether.
Short falls onto static material send the loads through the roof.
To reiterate for the umpteenth time. Ice tool tethers are to
stop your leashless tool from falling into oblivion should you drop it. They are NOT designed, tested, nor intended to catch you should you slip and
Any time you modify your gear you're potentially affecting something that you may not be aware of. Cutting off some excess straps off your pack to save
some weight is one thing, but modifying PPE (personal protective equipment) is another. Most gear manufacturers have gone through great lengths to
provide the equipment in the way it was intended, so it's likely better to just leave it that way.
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Kolin Powick (KP) is a mechanical engineer hailing from Calgary, Canada. He has over 20 years of experience in the engineering field and served as Black Diamond’s Director of Quality for over 11 years. He is currently their Climbing Category Director. If you have a technical question for KP, please email him at firstname.lastname@example.org and he will TRY to respond.
To help make more climbers safer climbers, Rock and Ice has teamed up with Black Diamond Equipment to present the information here.