I walked on top of Ed Viesturs during our Denali trip, but I think Chris will be better for that because he’s thinner.
No, not the guys. Rather, I’m talking about Ed and Dav’s signature insoles from Sole footbeds. Dav’s model is based on Sole’s Thinsport version, which is perfect for fitting in ski boots that you’ve sized conventionally.
Chris Davenport footbed from Sole.
On Denali we went oversized with our boots and used the thicker Viesturs signature model. For that we had to upsize one shell size. Either way, thick or thin, in my opinion Sole is the best aftermarket footbed you can get this side of hiring a professional boot fitter. They take a very small amount of heat molding if your foot shape requires, but can also be used out of the box as a nice supportive foundation for your wheels.
Dav’s model includes a laminated layer of heat reflective material. During testing of such radiant barriers last winter (with other footbeds, not Sole) I remain unconvinced this type of thing really yields anything more than a minuscule increase in warmth, and even that might be psychological.
But a layer of aluminum foil (or whatever) really weighs nothing, so I’ll continue to give it the benefit of the doubt. My testing was done by wearing the reflective stuff on one foot and not on the other. Not the most scientific, but I think after a dozen days of doing that one should be able to get a pretty good sense of what works and what does not.
Your thoughts WildSnow readers? Can a reflective radiant barrier really do much when it’s sandwiched in between plastic and foam layers in a boot footbed?
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There are 3 forms of heat transfer
1. Conduction: heat transfer through one material or between materials that are touching each other. I would imagine this is the most significant factor for heat transfer from your foot to the outside of the boot
2. Convection: when a hotter colder fluid (liquid/gas) moves from one place to another and in so moves some amount of heat. This then works with either #1 or #3. An example of this mechanism is how wind makes you colder (although probably the primary component of wind chill is evaporation of water)
3. Radiation: everything more the 0K (absolute zero) radiates heat in the form of photons. The amount of heat radiated depends on the emissivity of the material. Thinks that are rough and black tend to have a high emissivity (close to 1) and things that are lightly colored and shiny (like aluminum foil) have a low emissivity (maybe 0.1). Emissivity is almost entirely a surface effect.
So, the reflective layer will only do something if it’s on the outside of the laminate, and even then I doubt it would help much, but, maybe.
Radiation only occurs in a cavity, so if it’s sandwiched between two solid layers, it’s not going to do a damn thing.
Feldy is right, except that on #3, the amount of heat radiated depends more strongly on the temperature of the emitting body (T to the 4th).
Dan, that’s exactly what I thought, as every time I test the reflective type insoles they seem to make no difference… Also, least we forget, aluminum is incredibly heat conductive, so I’m wondering if having that layer of aluminum foil in there is actually counter productive (if it’s indeed alu, which it probably is…).
I am thinking about trying the aluminum foil thing, but; I have been using Sole foot beds in my shoes, and, hiking boots for years. I am still using the Superfeet custom cork insoles in my ski boots, but, I am wondering whether the padded Sole insoles might be better for touring.
Never toured with my Soles, but I think they’re similar in quality to Superfeet, which I have toured in a lot and like. I use the green Superfeet in my Dynafit boots.
Regarding fitting issues related to Scarpa shells not being flat under the foot: In my experience, Sole insoles provide a good fit in Scarpa boots because the bottom of the insole roughly follows the shape of the shell. The fact that the Soles are somewhat stiff under the arch and aren’t flat on the bottom makes for more even molding of the liners and takes up less space in the shell compared to flat bottom insoles. This has worked for me on a few different pairs of Scarpas with only minor tweaking required after initial fitting.
Thanks for the site,
See
See, exactly, if the high arch of the Scarpa bothers the foot, you use a footbed you can thin out in the problem area. In my experience doing so is rather tedious but does work and is how I fit Scarpas when necessary. For example, I used Scarpa Spirit 3 on Denali for my summit ski descent, and did something like that to eliminate the high arch. Lots of work to get it right, but it was worth it.
Hi Lou,
Thanks for the write-up. I am a bit late to the party, having been traveling, but better late than never.
As Dan said above, you need cavities between the reflective surface and the heat emitting object (your foot). We are adding more holes to the CD Thin EVA layer, so that the laminate has more air-filled pockets between it and your foot. This should increase the effectiveness. Testing of some new versions will be done by the end of September.
Regards
Rob, Product Director, SOLE
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