Author Topic: Carbon fibre sheet to stiffen soles for crampons?  (Read 756 times)

Garci013

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It is relatively inexpensive to purchase carbon fibre sheets with thicknesses between 1 and 3 mm which could be cut to go underneath the existing insole ( if there is room in the boot) and thereby stiffen a robust 3 season boot with normal flex from a b1 to b2 and enhance its use with crampons for winter walking. Has anyone tried this yet?

gunwharfman

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Re: Carbon fibre sheet to stiffen soles for crampons?
« Reply #1 on: 19:39:31, 30/12/20 »
I've never used crampons but I'm interested in the views of the people on this site who do use them.

richardh1905

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Re: Carbon fibre sheet to stiffen soles for crampons?
« Reply #2 on: 08:36:36, 31/12/20 »
Interesting idea, but better off splashing out on a pair of decent crampon compatible winter boots, in my opinion. If you just use these in winter conditions, they will last you years and years. Remember that you will be wearing thicker socks in winter, which will take up more boot space.


PS - welcome to the forum  :)
WildAboutWalking - Join me on my walks through the wilder parts of Britain

windyrigg

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Re: Carbon fibre sheet to stiffen soles for crampons?
« Reply #3 on: 09:28:36, 31/12/20 »
I've used Grivel crampons (G10) for 10 years now which are fitted with a flex bar. I have used them on several different Meindl boots (maybe Bhutan / Borneo ? models etc) without the slightest problem, I've never had a crampon come loose or pop off. None of the boots were rigid sole, just tough leather boots. I am now a walker and occasional scrambler rather than a climber but do go high.

pdstsp

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Re: Carbon fibre sheet to stiffen soles for crampons?
« Reply #4 on: 09:57:31, 31/12/20 »
Not sure I'd be happy to do that Garci013 - most crampon compatible boots at B2 have a "shelf" which the crampon engages with to ensure it doesn't slip, so if you are using C2 crampons you may be risking a failure just when you don't need one!  I use Grivel G12 with winter boots (La Sportiva)and these are great when conditions are steep and icy.  On more gentle days I use flexi-crampons and sometimes spikes on Meindl Bhutans and, again, they work well.


I think that I would be concerned that a crampon would pop off using non compatible boots - think of the stresses you put through the boot on a steep icy fell.


Of course I may be being a wuss.


Oh - and welcome to the forum from Liverpool by the way.
« Last Edit: 10:06:44, 31/12/20 by pdstsp »

Garci013

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Re: Carbon fibre sheet to stiffen soles for crampons?
« Reply #5 on: 11:29:47, 31/12/20 »
Thank you for the replies. I used crampons for a trip in the lakes in 1991 on my Scarpa Asolo, fully leather, cambrelle lined pre-gortex boots bought in 1882-3ish with a skywalk sole which were probably not b2s but were OK except very cold. Feet first of chesterfield replaced this awful sole with a rand and the sole unit used for Altberg Tethers recently at great expense but they have done a great job and they are now comfy and cushioned and probably a tad more flexible.
I had some Mantas 20 yrs ago which were not comfortable so sold them
I would contemplate some winter only boots, but I am a bit of a gear freak and my wife may veto this.
 
[size=78%]Pdstsp I am curious as to which model of La Sportivas you use? The Nepal series are really mountaineer boots and many say overkill although I have never found heavy stiff boots a problem when trying them in the past.[/size]

pdstsp

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Re: Carbon fibre sheet to stiffen soles for crampons?
« Reply #6 on: 12:12:20, 31/12/20 »
You bought boots in 1882?  ;D ;D 


I have sent you a reply to your pm as I saw that before the question here.  Trangos by the way.


Paul

Garci013

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Re: Carbon fibre sheet to stiffen soles for crampons?
« Reply #7 on: 12:37:41, 31/12/20 »
Thanks for your advice Paul. Feels like 1882 sometimes but actually it was only last century.


forgotmyoldpassword

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Re: Carbon fibre sheet to stiffen soles for crampons?
« Reply #8 on: 13:08:25, 31/12/20 »
It is relatively inexpensive to purchase carbon fibre sheets with thicknesses between 1 and 3 mm which could be cut to go underneath the existing insole ( if there is room in the boot) and thereby stiffen a robust 3 season boot with normal flex from a b1 to b2 and enhance its use with crampons for winter walking. Has anyone tried this yet?


B1 to B2 is less about the flex and more about it being able to take a flexi crampon which avoids that dreadful feeling of your crampon coming loose.  Most of the time it's not an issue, you stop and fiddle with it and get yourself happy - but if I was climbing gullies, anything with some vert then it'd be B2 minimum with a flexi crampon. Would suggest something if you give me a price range you're interested in, it isn't like you need a set of La Sportiva Cube's for bimbling up things but I'd consider proper boots a solid investment and key for safety.  Tell your wife safety equipment shouldn't be skimped on and you don't want her cashing in your life insurance that easily! :D

windyrigg

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Re: Carbon fibre sheet to stiffen soles for crampons?
« Reply #9 on: 15:58:58, 31/12/20 »
A few different comments above, none of which I disagree with.
Hopefully helpful rather than contradictory?
Maybe it comes down to where you intend to use the crampons?

BuzyG

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Re: Carbon fibre sheet to stiffen soles for crampons?
« Reply #10 on: 21:35:07, 31/12/20 »

Another who has Grivel G10's  I bought them to go with my old boots, which were a little flexible.  My current winter boots are very sturdy, so no issue there either way.  You can extend them to fit UK size14 boots too.  O0

Our local moors are pretty gentle and seldom see snow, so up there I wear Micro Spikes.  No good on steep ground  and they have no anti balling plate.  But for winter on the moors I find them a fantastic light weight tool, that will fit the most bendy of foot ware. :)
« Last Edit: 21:44:01, 31/12/20 by BuzyG »

Booga

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Re: Carbon fibre sheet to stiffen soles for crampons?
« Reply #11 on: 11:37:57, 03/01/21 »
My concern about using carbon fibre sheets under the footbed is that no matter how good the fit is there is always a chance of the sheet moving relative to the boot, or rather the flexible boot still trying to move whilst being restricted by the sheet and a crampon that it's not designed for, this could lead to wear and possible failure in unexpeted places.

I'd rather go for a crampon with a flexible bar such as the Kahtoola KTS or K10 which I could use on my current boots, or if I feel I really needed a B1/C1 combo I'd bite the bullet and buy some suitable kit rather than trying to alter something that's not up to the job.

kinkyboots

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Re: Carbon fibre sheet to stiffen soles for crampons?
« Reply #12 on: 12:09:33, 03/01/21 »
Any strength/stiffening in the sole of a boot (the midsole) is usually buried deep inside the sole unit hidden from view.

Carbon fibre is designed to have strength in one direction only and that's never across it's thinnest cross section. The slightest flex across this will cause it to shatter into thousands of pieces. The other downside to using carbon fibre in this context is that it has extremely sharp edges which will simply slice any lining material (including leather) inside the boot ruining it.

It's a non starter or it or a variation of it would be already on the market.
« Last Edit: 12:15:35, 03/01/21 by kinkyboots »

Dyffryn Ardudwy

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Re: Carbon fibre sheet to stiffen soles for crampons?
« Reply #13 on: 13:41:29, 03/01/21 »
Placing an expensive piece of carbonfibre, as a replacement insole, will be a waste of time, as you will still get flex from a boot not designed to use step in crampons

Full Scottish winter boots, designed to take step in crampons, have a steel plate actually built into the sole of the boot.
Ive still got a pair of very old 1991 Scarpa Fitzroys, which has a full steel plate built into the sole, and theres a little bit of flex due to it being a leather boot, but its still like walking with a pair of building bricks tied to your feet.

When i have used them during the summer months, which i know sounds a bit crazy, but the thickness and quality of the leather ensures they stay dry far longer than a normal leather 4season boot.


Your ankles and leg shins certainly know about it, once youve worn the things, but the boots are bullet proof.
Boots designed to take full step in crampons, need to be as stiff as possible, and the only way to achieve that, is to construct the sole with a inbuilt steel tensioner.
« Last Edit: 13:45:40, 03/01/21 by Dyffryn Ardudwy »

Garci013

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Re: Carbon fibre sheet to stiffen soles for crampons?
« Reply #14 on: 15:18:20, 07/01/21 »
Update.
Thanks for all the replies. I bought [censored] Breithorn Pro boots, made in Mallorca from Sportpursit for 150. The reason I choose these apart from price is that they are made of one piece of leather in the tongue are (similar to Altebrg Tethera/Nordkapp, Scarpa SL Activ etc) and therefore inherently more waterproof than boots with stitching in this area. They are also Gortex lined, though I am not sure this is an advantage. Though a "normal flex" they seem extremely robust and have needed some breaking in (similar flex to Scarpa SL). Being Nubuk I have treated them with 2 coats of neatsfoot oil and a thin coat of ledergris which has darkened these into a nice oily/waxed finish, being careful near the rand to avoid adhesive failure. They are similar to the Nordkapps but the fit is more generous. I am a size 9 (eu43). I need a size 10 in Altberg Nordkapps but in these 10 was far too big, 9 just OK and I now have very generous 91/2 EU 44 now which allow for a thin and thick pair of socks.
I have worn them in the recent snow on high ground and was very impressed. They are warm. I think they will be no problem with flexible crampons and do not possess the groove at the back for semi-auto ones.
Having bought a 1.5 mm carbon fibre sheet for 11 from eBay, I see no reason why this  could not be used to successfully to stiffen boots. Due to the weave, the sheet is strong to flex in all directions, edges can be sanded smooth and under the insole, if sized correctly  would not move (like any insole spacer). The reason why I will not use this though is because the c2 crampons mostly use the lever mechanism at the back to fix to the sole, which these boots do not have. Also if I am wrong about any of the above, I don't want to find out by falling off a mountain. I will no doubt find a use for the sheet in a DIY project sometime.