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Can we have a better XCD boot midsole?

Posted: Sun Feb 10, 2019 10:53 am
by bgregoire
lilcliffy wrote:The soft sole issue is a trend that I am seeing across the board in supposedly "heavy-duty" Nordic touring, hiking and backpacking boots. The trend is for everyone to expect a heavy-duty hiking/backpacking/Nordic touring boot to feel like a sneaker or birkenstock under your foot- right of the box! Boots in this class need stiff supportive mid-soles, both to provide stability and power transfer- BUT also to ensure the longevity of the sole.
Yeah, nothing better than a perfect fit in store for an easy sell! Also, as Alfa has let me know indirectly via e-mail, the space freed up by avoiding the use of a stiffer midsole material can be used for an insulating midsole, which is a great benefit when on long winter walks!

I've been thinking of this duality lately. Perhaps we are still lacking the perfect material to be used as a midsole that is 1) sufficiently stiff, 2)light, 3)insulative 4)durable? We can go super uber stiff and super light: kevlar fiber (no flex for tele though). We can go super light and insulative: EVA foam or similar (flop). The Med-stiff midsoles that are just right in terms of stiffness (usually some form of plastic (Nylon, etc.) are relatively heavy and not at all insulating. I'm thinking some R&D may be required here... Thoughts?

RE:A better XCD midsole?

Posted: Sun Feb 10, 2019 11:18 am
by Leo Tasker
I've been thinking of this duality lately. Perhaps we are still lacking the perfect material to be used as a midsole that is 1) sufficiently stiff, 2)light, 3)insulative 4)durable? We can go super uber stiff and super light: kevlar fiber. We can go super light and insulative: EVA foam or similar. The Med-stiff midsoles that are just right in terms of stiffness (usually some form of plastic (Nylon, etc.) are relatively heavy and not at all insulating. I'm thinking some R&D may be required here... Thoughts?
How about wood?

I used to have a pair of Montrail mountaineering boots with a beechwood midsole - they gave the boots just the right amount of flex, insulated pretty well and were durable too. Obviously there are issues with wood getting wet and being exposed to sub zero temperatures but these problems should be easy enough to guard against during construction. The boots were pretty stiff for use with rigid crampons, but it's surely possible to tailor the midsole flex to suit BC ski boots...

I wonder if, like down vs synthetic for insulation, Mother Nature has already provided the best material? She's had millions of years headstart, after all :lol:

RE:A better XCD midsole?

Posted: Sun Feb 10, 2019 12:58 pm
by lilcliffy
bgregoire wrote: Yeah, nothing better than a perfect fit in store for an easy sell! Also, as Alfa has let me know indirectly via e-mail, the space freed up by avoiding the use of by a stiffer midsole material can be used for an insulating midsole, which is a great benefit when on long winter walks!
Cool. Hadn't thought about this actually.

Hmmm...So this suggests that Alfa is determined to keep the boot very light- and is trading a stiffening midsole for an insulating one...Well that is pretty cool actually...

Weight comparisons:
1) Alpina Alaska BC (43EU): 1.92kg (from MEC site- per boot or per pair?)
2) Alfa Guard Advance (42EU): 725g- per "shoe"

Will try and get clarification on weight comparisons- or weigh mine!
I know that the Guard has an insulating mid-sole- no mention of this with the Alaska....

I've been thinking of this duality lately. Perhaps we are still lacking the perfect material to be used as a midsole that is 1) sufficiently stiff, 2)light, 3)insulative 4)durable? We can go super uber stiff and super light: kevlar fiber. We can go super light and insulative: EVA foam or similar. The Med-stiff midsoles that are just right in terms of stiffness (usually some form of plastic (Nylon, etc.) are relatively heavy and not at all insulating. I'm thinking some R&D may be required here... Thoughts?
Yes. Good stuff Ben.

RE:A better XCD midsole?

Posted: Sun Feb 10, 2019 12:59 pm
by lilcliffy
Wood.
Magic substance that grows on trees!!!
I love wood.

A better XCD midsole?

Posted: Sun Feb 10, 2019 3:26 pm
by bgregoire
woodsole.jpg
Any other ideas?

Re: Can we have a better XCD boot midsole?

Posted: Sun Feb 10, 2019 7:13 pm
by lilcliffy
I am very interested in this discussion, but know almost nothing about boot construction tech...

Here is an email I received back in January 2015 from Alpina in Slovenia- I was asking them about the Alpina 1600 BC:
Hello mr. Gareth

Here below are the answers to your questions:
1. The boot is made in Europe. Uppers are made in Romania and assembly in Slovenia.
2. Stiffness of the midsole that determines the sole flex is 35 Shore D. It is softer than the stiffness of the Alaska model.
3. The thickness of the leather is 2,0-2,2 mm. The thickness of Alaska leather is 2,6-2,8 mm.

Alaska model is generally stiffer boot than BC 1600. It is more reinforced and was developed for more demanding skiers. It provides better stability than BC 1600.

If you have additional questions don’t hesitate to ask and we will provide you our answers.

Best regards!

Janez Novak, Product Marketing
Alpina d. o. o.

Strojarska ulica 2, 4226 Žiri
What does "35 Shore D" mean? I wonder if all of these boots have a "Shore" classification?
Sounds like sailer talk to me... ;)

Re: Can we have a better XCD boot midsole?

Posted: Sun Feb 10, 2019 7:22 pm
by bgregoire
The Shore (Durometer) hardness test:
http://www.substech.com/dokuwiki/doku.p ... dness_test

On another note, insulation wise, this might also come in handy in our discussions!
https://gearjunkie.com/primaloft-gold-a ... insulation

Re: Can we have a better XCD boot midsole?

Posted: Sun Feb 10, 2019 8:26 pm
by paulzo
I don't think is is really that complicated in terms of finding a material. Back in the 80's when I worked in mountain shops, I sold a lot of Asolo hiking boots and ski boots. They had developed a nylon midsole, graduated thickness and flex for each boot size, with a short steel shank riveted to it under the arch. Called it Asoflex. They used it in hiking boots and in the late, lamented Glissade series of 3-pin boots, and it was a great thing. Durable stiffness, just enough; and of course they had the capability of making it more or less flexible by varying the thickness. Only issue with the concept in ski boots is that for 3-pins, it did not extend out into the duckbill, so the torsional stiffness limitation became the rubber outsole. But in an NNN-BC boot that wouldn't be an issue.
Of course, the Glissades had serious sole delam issues which doomed them - but they were great boots while they lasted, I had a pair and loved them. Asolo actaully fixed that, but too late.
If you ask me I think the real reason there aren't any stiffer midsole NNN-BC boots is twofold: one, little demand, and two, nervousness about building a boot so stiff it tears the binding apart.
The number of folks who want to thrash around in the woods and mountains, as opposed to either gliding along a snow-covered road or track or going out looking for turns as a central objective, is relatively small, and I suspect not enough to make targeting it worthwhile for the manufacturers. If a product niche is not being filled, and it wouldn't take any major innovations to fill it, the reason is almost always that it is so small as to not be profitable.

Re: Can we have a better XCD boot midsole?

Posted: Sun Feb 10, 2019 9:27 pm
by bgregoire

Re: Can we have a better XCD boot midsole?

Posted: Sun Feb 10, 2019 11:38 pm
by 12gaugesage
We need a t4/excursion in nnnbc. It would solve everything. :D
Gotta be a reason it hasn't happened. Is the binding just not strong enough? Can it really be much weaker than a simple 3 pin? Both rely primarily on 3 screws, similarly spaced to secure them. Or will the bàr rip out of the toe? The system looks more robust than tech bindings.
At this point it almost seems that the 75mm market still exists because nnnbc boots fall short. It's weird.
Makes me want to cut up a t4 toe and retrofit a bar into it.