Shoe Drainage Test: Part I

Motivation and Introduction

Motivated by the question of what shoe is best for challenging winter conditions, I set out to perform an experiment rather than trusting questionable internet resources, alternative facts, anecdotal evidence (“Never GoreTex!”), and my very own biased views. I’m sure I’m not the only person looking for a shoe that keeps you warm and dry in wet and cold conditions. I’m also pretty sure I’m not the only person who thinks that’s mission impossible. So let’s get some facts on the table and see whether all of this is a Schnapsidee or not.

I picked four shoes that have different characteristics and different pros and cons (see Figure 1). Two of them have a GORE-TEX® membrane, two don’t. Note that I don’t understand anything about shoes really. All I do is buy them en masse. Also, I’m neither married to a specific manufacturer nor to a specific model. Quite the opposite. I love trying out new shoes and it’s been one of my habits to rotate through a set of 3-5 different shoes at any given time. Without being able to present any hard evidence, I believe it has helped me to prevent repetitive stress injuries because every shoe is different. But that’s a story for another day.

For this experiment, I was first and foremost interested in finding out how these four shoes drain if they get wet inside. So I designed a simple experiment that is described below.

Methodology

Figure 1 shows the four selected shoes for this experiment. All except the Salomon Snowcross CS had some miles on them. The La Sportiva Uragano came out recently, so I don’t have a ton of experience with it yet. However, in the 100 or so miles I’ve logged so far in them, I was very impressed by their performance. I’ve successfully used the La Sportiva Crossover 2.0 GTX for two White Mountains 100 races and for other adventures, such as the Oregon 5 peak traverse. The shoe is similar to the La Sportiva Mutant, but it feels like it has a bit less support. The integrated gaitors work great in snow, but also works to keep sand, gravel, and rocks away. The Salomon Snowcross CS have spikes. I got them at the end of the last Portland snowpocalypse so that I could run-commute to work more efficiently, but never actually got to use them so far. A new version, the Snowcross 2 CSWP, is now available.

Table 1 summarizes the shoe data.

Figure 1. The four selected shoes: (A) La Sportiva Mutant; (B) Salomon Snowcross CS; (C) La Sportiva Crossover 2.0 GTX; (D) La Sportiva Uragano GTX. (C) and (D) have a GORE-TEX® membrane, (A) and (B) don’t.

Each of the four shoes was initially dry. Each was weighed (Figure 2A) and then placed on a wooden block of 3″×1.5″×0.5″ (Figure 2B) in a 13″×9″×2″ aluminum baking pan (Figure 2C). The purpose of the pan was to catch the water dripping from the shoe. The purpose of the wooden block was to keep the shoe out of the water.

The experiment was performed at about 72F room temperature.

Figure 2. (A) Each of the four shoes was weighted (dry); (B) A wooden block in an aluminum baking pan ensured that the shoe was not sitting in the water; (C) The water from the shoe will drip into the pan; (D) 483ml of water was poured into each shoe.

At time T₀=0min, the start of the experiment, 483ml of water—corresponding to the 500ml marker of the Toaks cup that I (ab)used for this purpose—was poured into each of the shoes. That corresponds to roughly 9,660 tear drops. I then weighed each of the shoes at times T₁=10min, T₂=20min, T₃=40min, T₄=1h, T₅=2h, T₆=3h, T₇=4h, T₈=5h, T₉=14h, T₁₀=17h to determine how much water was still left inside of the shoes.

I wasn’t entirely sure what to expect, except that I figured the non-GORE-TEX® shoes would probably lose all water rather shortly, whereas this would take longer for the GORE-TEX® shoes.

Results

The outcomes of the experiment are visualized in Figure 3. The horizontal axis represents time (in minutes), the vertical axis the percentage of water left in the shoe after a given time T. As one can see, the La Sportiva Mutant lost 75% of the water in the first 10 minutes. After 17h (1020min), about 7% of the water was left in the shoe. The Salomon Snowcross CS lost the water more gradually. After 5h (300min), 28% of the water was gone. 33% was remaining after 17h (1020min). Both GORE-TEX® shoes, the La Sportiva Uragano GTX and the Crossover 2.0 GTX were super leak-proof. After 17h, 19% and 9% of the water respectively remained in the shoes. Since there was none to very little water in the aluminum pans, most of the water was lost through evaporation. Figure 4 shows how some of the water seeped through the shoes.

So, clearly, a GORE-TEX® membrane keeps the water in the shoe very well, not just out of it. The Snowcross is surprisingly water-proof as well, even without a GORE-TEX® membrane. And not surprisingly, the Mutant drains very quickly because it has no water-proofness whatsoever.

Figure 3. The percentage of initial water (483ml) remaining in the shoe after a given time T [in minutes].

Figure 4. Examples of water seeping through the shoes (A) La Sportiva Crossover 2.0 GTX; (B) Salomon Snowcross CS; (D) La Sportiva Mutant.

Conclusion

So what did we learn from all of this? Well, there certainly is solid evidence that GORE-TEX® not only keeps the water out, but it also keeps it in. Perhaps that’s not so surprising after all. Yet, I don’t think I expected the two GORE-TEX® shoes to be so water-proof from the inside for so long. That means if they get wet inside, the only way for the water to get out is through the top and through absorption into the socks. So that’s potentially bad news. However, the experiment was probably quite a Schnapsidee indeed because, in reality, running in a shoe applies many forces to it that will help the water escape. So just letting the water seep though the shoe in a static setup—as I used it—is just not representing a real situation. A more realistic experiment would be to go for a quick run around the block before each weighing. That is for example what those folks seem to have done. And that is probably the experiment that I’d need to do next, if ever.

As it stands, GORE-TEX® shoes work great if you use them in conditions where nothing gets in. If you’re wading through rivers and whatnot, you are probably better off with a shoe that drains quickly and easily. You are still going to be wet of course, but there’s a higher probability that you will get dry again quicker if conditions allow for that.

However, it is conceivable that you are staying warmer in a GORE-TEX® shoe even if they are wet inside because there is less water circulation, which would cool your delicate feet down and ruin your run. So once you’ve warmed up what’s inside, it may stay and feel warmer. But that’s a hypothesis at best.

So what shoes should I pick for my next big thing(s)? I still don’t know. Dang! Perhaps I should drink some Schnaps now…

Disclaimer

The shoes were selected and purchased on my own. I’m not currently sponsored by any manufacturer and therefore have no conflict of interest. No shoes were harmed in the experiment. They were dried and will go back into service until they die of natural causes. The wooden blocks will be burnt in a campfire to roast s’mores, the aluminum pans will be reused for baking tasty lasagne, and the water was donated to the yard.