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Forclaz Trek 500 Merino Wool Backpacking Underwear

Sale price: $29.99 Regular price:

You no longer need to take a range of underwear with you when backpacking, as these pants come in a comfortable, natural fiber and dry quickly. The new solution for your hikes!

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Sale price: $29.99 Regular price:

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San Francisco, 735 Market St. Options

Select an available color and size to see options.

Model: 8544731

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Product Features

A photo of the Forclaz Trek 500 Merino Wool Backpacking Underwear in use

Forclaz Trek 500 Merino Wool Backpacking Underwear | Our team of backpacking enthusiasts developed these Merino underpants for backpacking comfortably in underwear made of natural fibers.

You no longer need to take a range of underwear with you when backpacking, as these pants come in a comfortable, natural fiber and dry quickly. The new solution for your hikes!


86% wool (6.7 oz/m²), fiber of natural origin offering comfort and softness.

Moisture wicking

The significant absorption capacity of the wool keeps the body dry.

Abrasion resistant

Use of wool fiber surrounded by polyamide yarn for protection.

Freedom of movement

Naturally stretch component for comfort and freedom of movement.


1.7 oz in size M (12)

Product Customer Reviews

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360 Reviews
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Forclaz  Trek 500 Merino Wool Backpacking Underwear,black
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It appears this product is made poorly.

There are lots of threads hanging off the underwear, I have not used them yet but first appearance is not good.

love them

just got my first pair of these and they are way better than any others I have had, will be perfe t when out treking this summer, definitely going to buy more

Hello Katrina,

Thank you very much for your review.

We are happy you are satisfied with your Trek 500 merino underpants. It' s a must-have for trekking!

Have a great day. ☺

Marie 🏊🏼‍♂️

Décathlon Canada

Very good but watch the sizing

These are great and a good price but the sizing chart is off - I normally wear a 10 or small, but from the chart a 10 comes up as medium. This is what I ordered and they were a bit loose. I've given them to someone who they will fit and ordered a size smaller

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Perfect fit

I would say colour more burgundy so bit disappointing as I’m a bright purple person also took out of packet and thought there sizing was totally out no way is my backside that big!! Tried on perfect fit for after swimming not tight but snug fit easy to get on when cold warm and dry really impressed

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Very comfortable

Wash well, true to size. Quick drying. Will buy more

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доволна съм

Страхотна покупка, леко скъпи, но си заслужава. Ако сте L размер си вземете M. Аз съм така и М-ката ми е точна. Мисля да си взема и лилавите.

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Благодарим Ви, че отделихте от времето си, за да ни оставите Вашата обратна връзка. Нашият екип следи всички канали, за да можем да подобряваме услугите си всеки ден. Ще предадем на нашите екипи всичко, което ни споделихте.

Спортни поздрави,

Екипът на Декатлон

Много меки

Много меки и удобни. Не стягат, топли са, въпреки фината материя. Хубав цвят. Лично аз бих могла да се пъхна и в по-малък номер от този, който ми препоръча размерната таблица, тъй като бикините са доста разтегливи. Много добро попадение.


Příjemný materiál.

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Nejsou špatné, ale dobrá by byla varianta s delšími nohavičkami pro větší pokrytí hýždí - doporučení manželky.

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Jsou více kalhotkového typu než na obrázku

Používám v zimě, jako druhé kalhotky na spodním prádle, protože se zdají tenčí. Tvar je spíše kalhotkový.

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Příjemné kalhotky

Mám už druhé. Jsou větší, takže beru o číslo menší velikost, než je navrženo. Příjemně se nosí, netlačí. Rychle schnou.

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kalhotky jsou volnější, budu vyměňovat za menší

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Kalhotky merino

Velmi pohodlné, skvělý materiál

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Skvěle odvádí pot a nestudí. Doporučuji zakoupit o číslo menší velikost než běžně nosíte.

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ideální do chladného počasí. Normálně mám L, tyhle by stačily M

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Size Guide

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Additional Product Information


Main fabric: 86.0% Wool, 4.0% Spandex, 10.0% Polyamide ; Yoke: 98.0% Wool, 2.0% Polyamide


A new yarn structure in which a polyamide yarn forms a thin sheath that protects the Merino wool fibers against friction and cuts

What is the fit of the backpacking pants?

These sports pants have a cut with an enveloping notch at the seat for superior comfort when hiking.

Freedom of movement

The flat seams provide good comfort throughout the day.The addition of spandex provides good freedom of movement.

How to wash your merino wool pants

Machine wash your Merino wool pants at 86°F on a normal cycle, preferably with liquid detergent. Dry flat. NEVER tumble dry.For more information: Visit our website

Tip before use

For more softness and hygiene, wash your briefs before first use.



Superior quality. Unbeatable prices.

For 40 years, Decathlon has delivered the best value in the retail sports industry by offering high-quality, sustainable and cost-effective products.

Decathlon makes the difference
  1. product-research

    Research and development

    delivers high-quality cost-effective products

  2. State-of-the-art production processes

    minimize manufacturing costs

  3. Optimized supply chain

    reduces retail prices

  4. laptop-checkout

    Minimal retail footprint

    lowers overhead and indirect costs


Size Guide Visual