Sweet Spot Backpack

My Failed Attempt to Cross Japan's Northern Alps

While living in Japan in the summer of 1999, I decided to hike across the Hida Mountains, also known as the Northern Alps. My plan was to start at Shinhotaka Onsen, a hot spring resort at the base of the mountains, and traverse Mount Nishi-hotakadake, Mount Oku-hotakadake, and Mount Yarigatake. According to AllTrails, the route spans 18.7 miles, gains 9,458 feet of elevation, and takes 15.5 hours to complete.

This was before personal computers and the internet were widespread in Japan, so my research was limited to whatever I could glean from a travel guidebook.

I also lacked appropriate gear. I don’t know what my 70-liter pack weighed, but I do know that my four-season tent weighed seven pounds, and my synthetic 0°F sleeping bag weighed over six pounds. I know, because I still have them. On top of that, I packed a thick wool sweater, a heavy synthetic-insulated jacket, water, and three days’ worth of food. Worse still, I was in poor physical shape. But, being an intrepid and impetuous young man, I decided to go for it anyway.

I took a bullet train from Nagoya to Shinhotaka Onsen and camped there for the night.

From Shinhotaka Onsen, I rode two cable trams up to Nishiho Hut, just above the tree line at 7,765 feet. I camped again, got up at 3:00 a.m., and climbed to the summit of Mt. Nishi-hotakadake, elevation 9,543 feet. The view was breathtaking.

The other hikers were laughing at my massive pack. They were carrying ultralight backpacks or just daypacks since they planned to stay at the mountain huts. I would soon discover exactly why they were laughing.

After I began ascending Gendarme, a semi-technical ridge at 10,377 feet, it became clear that my pack was too heavy and bulky for the nearly vertical climb. I feared I would lose my balance and fall thousands of feet to my death. My climbing method became ridiculous: I would lift the pack onto a ledge above my head, climb past it, reach down, haul it up again, and repeat. After many repetitions at a painfully slow pace, it became obvious that I wouldn’t reach a place to camp before dark. I admitted defeat and was forced to retrace my steps.

Here’s a video that a Youtuber (not me) took at Gendarme:
https://www.youtube.com/watch?v=D91FjUsaIrI

See what I mean?

The root of the problem was a combination of three factors: my lack of knowledge about the trail, my unwillingness to pay for lightweight gear for a single trip, and my stubborn insistence on camping without the appropriate gear. In hindsight, instead of hauling heavy camping gear, I should have stayed in the mountain huts like most sane climbers.

Let this be a lesson on how not to plan a backpacking trip!

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Fabrics for Backpacking Clothes
Part 10—Weaves vs Knits

Weaving interlaces two sets of perpendicular yarns–the warp (vertical) and the weft (horizontal), to create a stiff, strong, durable fabric.

Knitting interlocks loops of a single yarn to create a more flexible, stretchy, and breathable fabric.

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Fabrics for Backpacking Clothes
Part 8—Odor Resistance

Synthetic fabrics retain body odor, whereas wool does not. Wool’s odor resistance is often attributed to antimicrobial properties, but this is a myth. In fact, odor-causing bacteria survive longer on wool than on polyester. The mechanism behind wool’s odor resistance remains unclear.

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Fabrics for Backpacking Clothes
Part 7—Breathability

Breathable fabrics allow air and moisture v***r to pass through gaps between their fibers. Most moisture-wicking fabrics are breathable, but not all breathable fabrics are moisture-wicking. For example, cotton is breathable but not moisture-wicking.

The breathability of a fabric is determined mostly by its air permeability, which is influenced by multiple factors, including:

-Fiber type (cotton, polyester, etc.)
-Fiber composition (blends)
-Fiber cross-sectional shape (e.g., the non-round cross-sections of -Coolmax polyester fibers)
-Fiber longitudinal shape (e.g., the natural crimping of wool fibers)
-Fiber smoothness
-Yarn thickness
-Yarn structure (e.g., one fiber vs multiple twisted fibers)
-Yarn twist
-Weave pattern (plain, twill, or satin)
-Weave or knit density (thread count or weight per area)
-Fabric thickness
-Hot calendaring (flattening of the fabric during the calendaring process)
-Fabric finish (e.g., water-repellant coating)
-Fiber swelling in humidity (notably cotton)

If the above factors are held constant, natural fibers exhibit higher air permeability than synthetic fibers because their irregular shapes and surface textures create gaps between them, which facilitates airflow. Cotton fibers are highly air-permeable when dry, but they swell when wet, closing the gaps between them and obstructing airflow.

Although negligible compared to air permeability, other factors affecting breathability include:
-Hygroscopicity
-Fiber gas permeability
-Fiber surface energy (boundary-layer effects)
-Electrostatic charge behavior
-Water v***r diffusion through the fiber

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Fabrics for Backpacking Clothes
Part 6 — Moisture Management of Wool

A common misconception is that wool doesn’t absorb water. In fact, wool can absorb up to 35% of its weight in water, compared to 24% for cotton. So why is wool considered better than cotton for moisture management? The answer lies in the structure of wool fibers.

Wool fibers have a dual-layer structure:
1. An inner hydrophilic core that bonds chemically with water v***r.
2. An outer layer of overlapping scales, like roof shingles, with microscopic gaps between them. These scales are coated with hydrophobic lanolin.
(see illustration below)

Unlike cotton fibers, wool fibers don’t swell when wet. Instead, they flex, widening the gaps between them and promoting moisture-wicking capillary action.

Liquid water is wicked away from the skin to the outer surface. Since the fibers’ outer layers are hydrophobic, the liquid ev***rates, cooling the body during exertion or in warm weather.

Water *v***r*, however, enters the gaps between the shingle-like scales of the fibers and bonds chemically to their inner cores. The bonding reaction is exothermic—it slowly releases heat, making wet wool feel warm in cold conditions.

Summary:

1. Wool absorbs water v***r but allows liquid water to ev***rate
2. Wool absorbs a large amount of moisture before feeling wet
3. Wet wool cools the body in warm conditions
4. Wet wool warms the body in cold conditions

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Fabrics for Backpacking Clothes
Part 5 — Moisture Management of Cotton

Cotton is hydrophilic—it absorbs and retains moisture. When cotton absorbs sweat, its fibers swell and close the gaps between them, further preventing the transport of moisture. The water remains trapped in the fabric and against your skin, preventing ev***ration. In cold weather, the wet fabric conducts heat away from your body, making you cold.

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Fabrics for Backpacking Clothes
Part 4 — Moisture Management of Synthetic Fabrics

Moisture-wicking synthetic fabrics have spaces between their fibers that promote capillary action. Sweat is pulled away from the skin and transported through the spaces to the fabric’s outer surface. Because synthetic fibers are hydrophobic, this moisture ev***rates quickly.

Some manufacturers modify the structure of synthetic fibers to enhance their moisture-wicking capabilities. For example, Coolmax polyester fibers have non-round cross-sections that increase surface area to enhance capillary action.

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Fabrics for Backpacking Clothes
Part 3 — Moisture Management (Wicking and Drying)

Moisture wicking in fabrics is driven by capillary action, the same principle that causes water to rise through a narrow straw when its tip touches the water’s surface. In fabrics, water moves through tiny gaps between the fabric’s fibers, travelling from areas of higher humidity to areas of lower humidity. When you sweat, the higher humidity on the inside of your clothes drives moisture outward. However, if the fabric’s outer surface becomes wet from rain or high humidity, the direction of moisture movement can reverse.

Hydrophobic (water-repelling) fibers allow moisture on the fabric’s outer surface to ev***rate quickly. Ev***ration is an endothermic process—it absorbs heat away from your body, keeping it cool while you exercise and sweat. When you’re at rest in cold weather, the fabric keeps you warm since it stays dry.

Hydrophilic (water-attracting) fibers hold onto moisture, keeping the fabric wet. In cold weather, wet fabric conducts heat away from your body, making it cold.

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Fabrics for Backpacking Clothes
Part 2 — Fabric Properties

When choosing fabrics for clothes, some important properties to consider are:

Warmth (dry and wet)
Water resistance
Moisture wicking
Breathability
Drying time
Abrasion resistance
Strength-to-weight ratio
Odor resistance

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Fabrics for Backpacking Clothes
Part 1 — Fabrics and Their Uses for Backpacking Clothes

I previously posted a series of articles about fabrics for backpacks, tents, and sleeping bags. This new series covers fabrics for clothes.

See the table below.

To be continued

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Will You Be Killed by a Bear?

In the table below, all statistics, except those for bear attacks, are from the US National Park Service (NPS). The NPS doesn’t provide statistics for bear attacks, maybe because the number is too low to be worth reporting. From 2014 through 2019, NPS reports three deaths caused by wildlife but doesn’t specify the kind of wildlife.

The bear-attack statistics are from Vox’s meta-analysis of news archives about attacks since 1900 in all public lands listed in the table.

In national parks, the leading cause of death is medical problems such as heart attacks and strokes. Second place is roughly a tie between drowning and motor vehicle crashes.

In the table, the number of deaths by vehicle crashes in these areas is over 1,600 times the number of deaths by bear attacks. The actual difference is greater because state recreation areas are not included in the calculations.

Why are there so many deaths by car crashes in national parks? Driving in national parks is no more dangerous than driving in your city. The number is high simply because driving is always extremely dangerous no matter where you drive. Oddly, many people drive every day without a second thought but fear being attacked by a bear while hiking in bear country.

Just because the probability of an adverse incident is extremely low doesn’t mean you shouldn’t take precautions. But keep things in perspective!

The link below is the most clear, concise, and accurate article I’ve found about what to do when attacked by a bear:

https://www.nps.gov/articles/bearattacks.htm

Bear safety gear:

https://sweetspotbackpack.com/bear-canisters-bear-proof-bags-bear-spray/

Bear canisters:

https://amzn.to/3VPxSSI

https://amzn.to/3KzOo6X

https://www.rei.com/product/246158/rei-co-op-traverse-modular-bear-canister

Bear bags:

https://amzn.to/48Nk4j6

Odor-proof food storage bags:

https://amzn.to/4pVDIzE

Bear spray:

https://amzn.to/4h1h452

Fabrics for Tents, Backpacks, Sleeping Bags, and Shells
Part 5 - Waterproof Coatings

Fabrics are typically waterproofed with one or more of the following coatings:

- Polyester urethane (PU)
- Silicone
- Polyether urethane (PE)

PU-coated fabrics are inexpensive and are commonly used for rain gear and tents. Although waterproof, they absorb water over time, making them stretchy, saggy, and susceptible to mildew. This is because PU is hydrophilic—it slowly bonds to water while preventing it from passing through.

Silicone-impregnated fabrics have high tear strength, stretch resistance, and mold resistance, and they don’t absorb water. They’re also expensive. Silicone-coated nylon, or silnylon, is typically used in mid- to high-end tents.

PE is rarely used, except in high-denier floors of heavy expedition tents.

DCF is inherently waterproof and doesn’t need to be coated.

This is the end of my series on Fabrics for Tents, Backpacks, Sleeping Bags, and Shells.

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