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The cold world of alpine climbing.

The cold world of alpine climbing.

Wednesday, August 24, 2011

Crampon durability? Stainless or Chromoly?



Up front, I currently own and use crampons from Camp, Black Diamond, Petzl, and Grivel.  I still own Salewa and Chouinard crampons that I have pulled out a few times in the last decade or so and even older Chouinards and SMCs that I haven't used in this century.

The point is I have no loyalty to any crampon maker.  I just want them to fit my boots and then stay on the boots while I am climbing on them.  As you might imagine with crampons in my gear room that I used 30 years ago I look for reliability and at long term durability as well.

These days with the emphasis on mixed climbing (read rock climbing)  in crampons you can easily go through a set of crampon front points in a season or less, if you choose to participate.

So a crampon with an easily replaceable front point makes economical sense.  But I have yet to see a crampon with easily replaceable front points that I really like...for a number of reasons.

So if you like fixed front points, as I do, you'll likely look for crampons that are the most durable and just as important the most reliable.  The reason behind this particular blog and its information/opinions offered is simple, losing a crampon on route or having a crampon failure while in use can be serious.  Fatally serious. That reality bought me to the obvious...a closer look at the quality of the steel used and different manufacturing techniques.

OK lets talk steel?  But what does a guy writing a climbing blog know about steel?  In this case enough to make an educated comment from the quality and durability of steels and the manufacturing processes currently being used to make crampons.  As a professional I've designed and built literally hundreds of extremely high quality and very expensive small arms, small arm parts and custom knives from plate, bar stock and from forged, stainless and chromoly steels.  One requirement that each has is they must last generations of hard use, not just a season or two.




Call me an well educated consumer for climbing hard goods..  My background in the small arms industry  gives me some insight to recognise the differences between actual forged parts or parts cut from plate or bar stock, the heat treat, hardness and the differences in chromoly and stainless steel alloys.   It isn't difficult to apply that knowledge to climbing  gear at a basic level.  Several decades of ice climbing and the use of virtually every high performance crampon in that time frame lends me an idea or two that might not be obvious at first glance by a casual climber or one simply not "into" the gear.  This is a detailed gear commentary I think needs to be heard again in the climbing community.  As you will see I am a not the first one to have raised the issue of using chromoly and stainless in crampons

More on steels:

http://en.wikipedia.org/wiki/Stainless_steel

http://www.asminternational.org/portal/site/www/SubjectGuideItem/?vgnextoid=e0b0b4d68558d210VgnVCM100000621e010aRCRD
http://en.wikipedia.org/wiki/Steel


*Some materials and finishing perspective that needs to be considered first*

Working with a bare metal finish is a challenge for anyone, including skilled craftsmen.  There is nothing to hide a flaw. Doesn't matter if it is a small arm or a crampon, bare metal is always tough to work with.  There is some obvious protective value to most metal finishes.  But most protective finishes, especially "black" finishes will hide some pretty glaring faults/flaws as well.  Faults you could never get by with on a bare metal finish like stainless.

Bottom line here?  BD is allowing you to easily see every flaw in their stainless.  Almost everyone else is using some type of paint finish to protect their chromoly and just as importantly...look good cosmetically.

On the sells room floor cosmetics are king.  In the real word cosmetics mean ZIP.  Nothing!  Function and durability mean everything.  That goes for crampons and small arms.   Who has complained they were shot with an ugly gun?   Does the mtn care about the color of your crampon?

It is easy to find flaws in metal work if you look hard enough.  Just easier to see them in bare metal, that is in  "the white". The photo below is is an example of four different bare metal, "in the white" finishes on stainless. 



Four finishes on chromoly steel that  was then final finished with Carbona Blue for cosmetics and a low level of base metal protection.



The issue of flaws, in finish work or how you produce a product, can easily be over come.  You just need to use a material that structural or cosmetic flaws won't have a negative effect in the market place.  Problems result when your base material can't live up to your design work, for the use intended and the product fails in use.  Or your marketing department gets carried away with unrealistic claims.

The choice of material is critical when you have complex shapes, as you do with modern crampons.
Flaws cutting and bending in the manufacturing process that have long been accepted with chromoly, and no ill effects, simply may not work with in the same process with stainless.  Durability for stainless alloys and the heat treat being used seems barely in the same ball game as time proven chromoly.


Petzl's handiwork in chromoly and a black painted finish
dbl click to get more details

Grivel's handiwork in chromoly and a black painted finish
 dbl click to get more details

My perspective on gear breakage

If you have climbed ice long you have likely seen gear break.  The gear that does break in our sport is commonly known these days, or should be.  It is true that crampons, tools and picks have broken in the past (for decades) from every brand.  Anyone that tells you the failure of current production gear is the fault of your climbing style, boot sole rigidity, or climbing ability is simply ignoring the real issue.  The real issue is more likely one or more of the following, poor quality materials, lack of quality control and or bad design work by the manufacture.

Sure you can still break things ice climbing, but trust me, you will have to work at it for any of the quality  gear available today..

I personally haven't broken any ice gear in the last decade.   But I am also very critical on my choices in gear and I visually inspect them often.

I have worn out 3 pairs of crampons.  An early pair of Chouinard rigids by over sharpening.  My mistake which I have not repeated.  The other two pair were Darts.  Worn out simply by using them on modern mixed (read mostly rock) and having to sharpen them enough to keep them working on ice.   Fair enough in all three cases.  All were chromoly and all were forged front points.  Totally different designs or course but that isn't relevant to this conversation.

So here is what I know and what is generally accepted common knowledge in the small arms (guns and knives) manufacturing industry.

High quality stainless steel alloys are "soft and sticky" in comparison to chromoly used for similar applications in both plate and forged form.  And no, before you ask, the "sticky" part isn't going to make a difference climbing rock.

Take any quality knife for example.  If you want a durable and sharp edge you don't use stainless, you use chromoly.  If you want inexpensive weather resistance,  say from salt exposure, stainless might be an option.  A table knife you want to toss in the dishwasher?  Perfect.  Stainless is one of the most common and least expensive steels.  Much of it recycled..  It is also the cosmetic winner and the lowest common denominator for actual performance every where else.   If you require a sharp edge that is durable, and long term weather resistance, you use chromoly.  Depending on the level of protection required one of several coating options for the base metal.

The edge and the durability required can be a crampon point, a knife edge the professional requires or a hammer that has to cycle a million rounds of ammo.

Bottom line...if you want it to last,  you use chromoly and if required, a protective coating.
I would have to be convinced otherwise that a chromoly crampon would need a protective coating past cosmetics.  I know from experience that even simple powder coating is beyond the end use requirements to protect the steel on a crampon.  The "normal* coatings we use in my industry are way beyond what will ever be required in climbing gear.  As a side note.  The one instance of a climbing manufacture using a *normal* industrial level coating that I know of ended in a complete disaster.  Simply because the manufacture had no idea of the down sides of the actual coating being used.  Down sides?  Lubricity and brittleness in a fastener. Their reason for the coating process?  Cosmetics!   

Forging?  Forging is expensive.  The basic idea is to align the molecules  in the metal to add strength and durability to your product.  You can forge stainless and chromoly.  Forging will add to the durability and service life of both stainless and chromoly alloys if done correctly (hot forged ) and with the addition of a  proper heat treat.

"Forging can produce a piece that is stronger than an equivalent cast or machined part. As the metal is shaped during the forging process, its internal grain deforms to follow the general shape of the part. As a result, the grain is continuous throughout the part, giving rise to a piece with improved strength characteristics.[3] Some metals may be forged cold, but iron and steel are almost always hot forged. Hot forging prevents the work hardening that would result from cold forging, which would increase the difficulty of performing secondary machining operations on the piece."

More here on forging:
http://en.wikipedia.org/wiki/Forging

The beginnings of a BD stainless crampon.


Cutting from plate?  It is a less expensive method of manufacture compared to forged.  Basically cookie cutting by some method from flat steel plate and then you cold bend and finally heat treat as required.  General observation....durability compared to a forged product...will be less.   Again,,general observation..price point in manufacturing is the objective here.  You can use both stainless or chromoly as a material in this process.  Either will cold form, both will crack if not done correctly prior to heat treat.  Flaws from the cutting or bending process, stress risers, become points of failure if the cycle rate of the design  isn't high enough. (see the detail pictures below)

Cutting or forging....two totally different methods of manufacture and two totally different price points for the manufacturer.   But may be not the consumer.  You may not get what you pay for. There are always choices in any manufacturing process.   The trick is to know what choices to make, what can be combined in the manufacturing process and  most importantly, why.

Everything I have stated is really basic info to anyone working metal.  Not all the details are there, and to be honest as a climber the details are trivial.  Gear either works as intended or it doesn't.  A simple Google search will give you more info than you will ever require on steels and manufacturing processes.

So what is the bottom line?  Who cares about stainless or chromoly, forged or cut from plate?

There are some easy comparison to make given enough time.   But there are other issues as well.  Does size matter?   It certainly does in raw materials and production costs.   How much the crampon covers on your boot sole and does it make a difference climbing? That I'll leave that up to your imagination.



A '80s vintage forged Chouinard/Salewa on the left with 6 down points. A plate cut stainless BD on the right with 6 down points for the *same size* boot sole.  It should be obvious which pattern offers the most traction on snow and ice.  How much is enough?

Below Chouinard/ Salewa Hnged,  hot forged, chromoly crampons.  Bought in 1979 and used all over the world on ice and mixed.  Notable..mixed climbing...the Chouinard/Beckey/Doody  route on Edith Cavell, Canadian Rockies.  And literally 1000s of feet of water ice and easy mixed.  I've never heard of a pair of these failing in any manner.  But no Internet for much of their life span either..  Weight 204g for one front half.


Chouinard /Salewa's front points after years of use.



Black Diamond Stainless Sabertooth. stainless, cut from plate and cold formed.  Known catastrophic failures with this crampon technology on complicated designs.  Total use on this pair?  Two trips up the Cosmic Arete, early March 2011.   Maybe 10% of what the Chouinard/Salewa Hinged above did on just the North face of Cavell.  Weight 142g for one front half (stripped w/no bail)







Current production BD Stainless Sabertooth Crampons after only a few hours of climbing on moderate mixed terrain.  Dbl click the photos for a close up view.


Two sides to every story.  And admittedly I only see a small part of even my side on this one.  I admire innovation and on first impression you might be able to make a case for stainless as a reasonal base material for crampon manufacture.  Misleading infomercials aside the manufacturing techniques and alloy chosen would have to be up to the task as well to reap the real benefits of stainless in a crampon.

To follow the next part of the discussion please view the BD product video linked below.

Upgrade to stainless: The benefits of Black Diamond stainless steel crampons. from Black Diamond Equipment on Vimeo.


Making a *direct comparison to the best chromoly technology* used in crampon manufacture here are my observations and comments to the BD the video.
BD claims these benefits (in bold print below) to their stainless in their video and my answrs to those claims.


More "green" manufacturing.  yes, better than adding a coating, check.
No rust. stainless will still rust, better than Chromoly for rust? Sure.                                                                   
Wears better in use.  Sadly not what I have found in use and not the consistant history of stainless.
Extremely hard.  Not even close to chromoly.
More durable.  Again not even close to chromoly. 
Stronger.  No, chromoly is generally stronger in use
Lighter. chromoly and stainless weigh the same..the same.

Of course you could argue the point with different variations of stainless and chromoly alloys and the terms, "extremely hard", "more durable" and "stronger".   Just my opinions, based on my own experience, that are expressed here.

Below is a production (not a sales sample) Sabertooth Pro failure from last winter. And not the only pair with similar stainless steel failures I documented in the 2010/2011 winter climbing season. BTW all of the failures I am aware of have been either in the the EU or Canada.

To be fair likely the biggest retailer in the USA has no problem with the durability of the BD stainless crampons. I was made privy to the BD returns at REI for 2010/11 and the % was extremely low. Returns of BD crampons at REI for any reason are well below anything to raise their corporate concerns.




Comments below are from the owner of the broken crampons pictured above:

"The boot is/was a Nepal Evo bought in 2010. Size 42.5. The crampons only really had 10-15 days on them (I originally posted 20 but I was being overly conservative). I do weigh in at 200lbs but am not aggressive with my kicks. The majority of the days climbing were on tame WI3 as a seconder with a few days leading. By no means am I an expert but I would not say that they were seriously abused in such a short time and with relatively low impact climbing. In total, there were three days walking up grotto falls. Three days at Chantilly, climbing no walking. 4 days at King Creek, only climbing and two days on THOS. Not a lot of mileage...

Hope that helps,
Blake"


FWIW  the Grivel G12s I'm climbing on in the picture below have been on much more modern mixed than a couple of laps on the Cosmic Arete and show virtually no significant wear on the front points.  They are still going strong with a second owner.




You don't have to be a materials engineer or a rocket scientist to see what is happening here.  Similar wear patterns on both sets of crampons.  Just a lot more wear in a short amount of time on the stainless version.  You have to be extremely naive to believe the marketing pitch of better manufacturing techniques and the use of a higher quality of material.  I was originally.  I have been aware of the issues in manufacturing and production on this subject for several climbing seasons.  But I hadn't had the time to field test the stainless long term to my satisfaction until now. 

Photos below are the micro flaws (stress risers)  in plate cut stainless crampons.  The most recent pair are coded *1069* (69th day of 2011) the oldest *0168*.  Given enough use/time, IMO,  these will eventually fail. See if you identify the manufacturing flaws in these photos.

The next three pictures are close ups of the front points.












And small cracks starting on the outside edge of two different frames that will likely end as a catastrophic failure if you continued using it.





The lesson here is to be sure you visually check ALL your gear at the time of purchase and prior to every use!

Petzl, Grivel and DMM have a choice and are still using chromoly.  Camp beat BD to market with a stainless crampon.   That is the Camp •"Sandvik Nanoflex® stainless steel for superior performance and durability."

Black Diamond has a very good marketing department.here in the US.    Claiming among other things "stainless is lighter than chromoly".   Which is of course is an incorrect statement.

Facts I do agree with?
Nice that Grivel has written them all down :)  When I first saw this info on Grivel's web site a few years ago I put much of it off to childish bickering between two companies fighting over market share.  After all didn't everyone want some pretty new crampons?  I certainly did!   But no doubt some truth to Grivel's published info.  Now?  I am more concerned about what I strap on to my own boots.  And I worry less about who originally pointed out the down sides of stainless.



If you bother with a search of this blog you will find a few positive commentaries on BD stainless crampons. Specifically the newest stainless Sabertooth and Serac crampons.  I like those model's overall weight and climbing on them even more so.  I still think the Sabertooth is one of the best all around crampon designs  we have seen to date.  But good design work will seldom overcome a bad choice in materials and poor manufacturing techniques if the tool is pushed to the extreme.  And crampons are always pushed to the limit.  

Mark Twight and Will Gadd have both, at one time or another commented  in print, on just how well the Sabertooth  (the previous chromoly version anyway) climbed.   

More on my thoughts of how well the Serac and Sabertooth designs climb.



Fun to see BD sponsored, Colin Haley climbing on the Midi in the Sabertooth.
 
from Bjarne">http://vimeo.com/user5490470">Bjarne Salén on Vimeo.https://vimeo.com">Vimeo.>

Earlier that month I had soloed the same gully.  I made the decision not to use stainless there because I was concerned about reliability. It is not a difficult climb but not one I want to have a crampon failure on either, roped or unroped..




Stainless steel might be an upgrade for your kitchen appliances but it is not an upgrade when it comes to a sharp kitchen knife or ice climbing equipment.  There are simply too many trade offs to not question the use of  stainless in crampons.  
 It is all a matter of trust.  Spend your money wisely. 
 My money (and boots) are now on Chromoly. 

And a follow up..... that adds to this conversation



22 comments:

AlanL said...

Might I take a moment of your time for a question that is entirely unrelated to crampons? Knife steel. As a not particularly educated kitchen knife user, I hear peple referring to "stainless" and "carbon steel". Is "carbon steel" the same as "chromoly"? Or is there a whole other class of knife that I am too dowmarket to be aware of?

Most of my kitchen knifes are still stainless, albeit decent stainless (Wüsthoff, Global). I bought some cheap carbon steel knives to expermiment with: a Mora, an Opinel, a couple of little cheapie German paring knives. I find they're great, and the little carbon paring knives have quickly become my most used everyday knives in the kitchen. Next on the agenda: a bigger Japanese "carbon steel" knife.

But the thing I've noticed, and like, about the non-stainless knives, is how *easily* I can get a very good edge on them. I don't understand how that can be compatible with them beng harder.

Dane said...

Sorry Alen this would be a never ending thread if we get into knives and steels. Chromoly is different than Carbon steel. And most knives will be carbon steel alloys not Chromoly alloys. Firearms are generally chromoly, knives are not.

More here on carbon:
http://en.wikipedia.org/wiki/Carbon_steel

But no question *in general* either can be sharper than the typical stainless. But there are some really good knife stainless steels as well. Like many things it just takes more money :)

Th problem with talking steels *in general terms* is the more specific the answer the more likely you are to be wrong.

Knife steel is another animal than the discussion on the blog. But "hard" as in stainless knife steel is difficult to sharpen because it is physically hard. Carbon steel is easy to sharpen because it is physically soft. Same reason you can get a carbon steel knife sharper than you can a stainless knife. The thinner the edge the sharper the tool and likely the shorter the time the knife will stay sharp.

Obsidian knives are the sharpest because they can be napped toan incredibly thin glass edge. "Because of this lack of crystal structure, obsidian blade edges can reach almost molecular thinness".

How long a knife edge lasts depends on the edge bevel you can obtain. A wide V edge wil last a long time but never be very sharp. A long narrow V edge will be very sharp but not last very long. Hardness and steel toughness being equal on both.

Just don't get all that confused thinking it will apply to crampon steel. It doesn't.

Ian Armstrong said...

A well informed article Dane, I shared your concerns when I first saw the BD advertising train set off a year or so ago. The use of stainless in my opinion is about bling and built in obsolescence rather than the correct choice of material. I am a metallurgy graduate and ex steel worker so I have a rudimentary understanding here, albeit from a hazy 20yrs ago. Hats off to grivel and pretzyl for not jumping on the bandwagon, yet.

A little material knowledge goes a long way; a friend's grivel axe pick suffered a fatigue failure, I was able to identify this, a visibly large inclusion at the stress concentrator between teeth. Route completed with a bit more work, new axe from grivel (hats off again).

I mentioned the other day about building a prototype perfect pon. Obviously, no coating on these or perhaps the old chalk and ink NDT to prove there are no cracks?

All the best

Julian said...

Thanks for a very informative article Dane. I'm not giving up my chromoly Cyborgs any time soon.

Rich said...

Useful article. It bears noting that stainless steel DOES oxidize, albeit differently. Cheap stainless will certainly "stain" and, importantly, pit. These deep divots are stress concentrators and sources of microcracks. Not a big deal for your IKEA picnicware, but important for the business end of a torqued foot placement.

Somewhat like crampons, (machine)tool steel must also remain sharp while subjected to enormous stresses and is NEVER made from stainless steels.

fulton said...

Great write up Dane and btw if my crampons fail me while climbing and survive I'll take them out back and shoot them.

Dane said...

Good thing too, as you old guys? We'd just shoot ya anyway once ya break a leg ;)

marcello said...

thank you thank you!!! This was very informative!
I love the pics you posted of the Damascus steel, so artistic, so like wood.
I do not know a lot about crampon and gun steel ,but I know a fair amount about kitchen knives. Anything from ceramic to steel.

Chris (i-cjw.com) said...

First time visitor, and instant convert - looking forward to going through all your back posts in search of further inspiration.

Ryan S said...

Hey Dane,

Thanks for the post. It helps to clarify things for those of us who have slightly less understanding about materials. Additionally, it is important as a climber to know your materials fairly well.

I had noticed that the new BD crampons all have a smaller footprint, which is a bane for guys like me who have size 14-15 boots.

I have a stainless pair of Sabretooths, and while I do love the design, I have noticed that they wear quickly. I mixed climb a ton and those stainless crampon frontpoints are only going to last me one more season (for a whopping total of 2 seasons) They've only been sharpened once or twice but wear very rapidly.

I've broken a lot of BD picks too, like many others, and feel that there are probably manufacturing flaws at fault there. A few seasons ago I went through 3 pairs of BD picks in one season (they bent, broke or wore out fast, in some cases cracking at the tip immediately!). Conversely, forged Petzl picks routinely last me more than a season, and while they do bend I've yet to snap one (I have broken the frames on a pair of forged Grivel G-14's though).

While I do like a lot of the BD stuff (I love the Cobra's despite prematurely worn picks) I think they're working the advertising angle pretty hard and anticipating that things will mostly go their way due to the fact that many users don't use gear all that often or harshly.

Thanks again and keep up the great work!!

Clyde said...

It's a bit misleading to lump BD and CAMP together when discussing the use of stainless in crampons. The design and materials are entirely different. You may not like modular crampons, which is a different discussion (and a point of disagreement), so their Vector Nano isn't for you. And their XLC Nano certainly isn't for mixed climbing. But it's worth pointing out that *some* steels with stainless properties can be harder and more durable than chromoly. And they can make an excellent crampon that is lighter. Note the Vector uses hot-forged chromoly front points and the vertical frame is a Sandvik steel.

BTW Alan, I ditched all my Wusthoff and Henckels for Japanese brands you may not have heard of but are far, far superior. No faux-Damascus cladding or other gimmicky designs. But as Dane said, that's outside of this blog's scope.

Dane said...

"It's a bit misleading to lump BD and CAMP together when discussing the use of stainless in crampons. The design and materials are entirely different"

Agreed and never intended to make the comparison as they (BD and Camp) use totally different stainless alloys and designs for the crampon frames.

When you start making general statements like "it's worth pointing out that *some* steels with stainless properties can be harder and more durable than chromoly" you have missed the conversaion. Because any steel can be bettered depending on application required.

Better to compare the tools..as in crampons durability...in this particular case the BD stainles is not holding up to the intended use.

BTW...I do like modular crampons. Just not for every use. Crampons are just tools, like a hammer. I own a lot of different style hammers. And happy that I have the options when one is required :)

Anonymous said...

"Fun to see BD sponsored, Colin Haley climbing on the Midi in the Sabertooth."

- What is the name/grade of the route? Looks fun!

BR, Icenoob.

Dane said...

I've heard it called the Passarelle gully, but I think that is just another name for the Cunningham Coulior.

It is the first and shortest gully on the north side of the gully under the bridge (passarelle).

It is feed buy the WC in the Midi tunnel system. Which makes for some brittle ice :)

No clue on the rating.

Wyatt said...

So what IS the deal with Sandvik Nanoflex? Is it just marketing BS? Are their claims at http://www.camp-usa.com/product-highlights/forum/sandvik-nanoflex.asp#stronger true? They downplay the importance of rust resistance, but I wonder why they chose to use a stainless based material? Personally, I don't find the Vector Nanotechs to be that much lighter than a crampon like the Dart, and the shape is poorly designed for climbing, but I have to admit the steel is ridiculously hard. Does this material have promise?

Anonymous said...

Hi Dane,
Just took my 10x scale lupe to the susceptible areas of my ss sabretooth crampons. Yes there is an incipient crack between the outer front point and second point on my left crampon.

Used maybe 20 days for single pitch water ice and trad mixed last season.

Wear, about the same as yours from the Cosmiques.

Oh, I'm a lightweight, 60kg

Regards
Magnus

Dane said...

Magnus, glad you found the problem with a loop and not on lead. Thanks for the feed back.

Wyatt? sandvik-nanoflex? My take is, a good alloy was used but a poor design. They saved weight by using a thinner material. So thin the crampon now flexs. Problem with all this is hitting a price point that climbers will pay for.

Again just an opinion, but some where along the line climbing gear started being designed for price not for the end user.

Anonymous said...

FWIW... saw one broken sabertooth (SS)very new here in the adirondacks...


a very good site in general Dane...

jhh60 said...

What's your opinion of the current generation BD Cyborg? Stainless frame, standard steel (chrome-moly?) front points? Could be a reasonable compromise...

Illimani94 said...

A shame I stumbled onto Cold Thistle AFTER I bought a pair of the SS Sabretooths last spring. After concluding their 10th ice season (w/ 2 Bolivian expeditions thrown in) my old cromo Sabres are looking a bit beat up. Now the hard choice: try the new SS Sabres or bite the bullet and ditch them for something else. A shame - like you, I think the Sabretooth is one of best crampon designs I've used. On the other hand, I'm 59 and unlikely to heal quickly if I take a winger from a busted crampon.

Ian said...

Dane,
I have had the same Selewa crampons as in your picture since the '70s, lots of vertical ice and Scottish peaks and no problems. The points have lost 4 or 5 mm with sharpening (to a chisel point). I have just replaced them with a newer same pair from ebay.
Don't like the modern toe/heel bale centre-bar design, seen more than one centre-bar fracture. The crampon then comes completely off, very dangerous on steep ice. The Selewas have 6 top strap posts that brace the boot laterally, so they don't need a laterally stiff centre-bar as on the toe/heel bale type to avoid the crampon coming out of the bales (my son had this embarrassment, fortunately I had him on belay at the time), and two separate straps, so you will always have half a crampon left to get out of trouble with.
Thanks for the article! - Ian

Dane said...

Thanks Ian. I do find the durability/relaibility of the older crampons interesting compared to some that are available now. First crampon I had seen with a binding was stuck in the ice just above the Difficult Crack on the Eiger. Just one mind you. Not a pair :)