Book an appointment at the Hereford Service Centre:

Arcteryx Mens Beta AR Pant Black

£259.00 £370.00
30% off

Customer Rewards points earned with this item.

Other colours available:
Arcteryx Mens Beta AR Pant Black

Possibly the best mountain waterproof pant for all-round use. The Beta AR Pants from Arc’teryx are a 4 season over trouser with exceptional fit and functionality. Constructed out of durable GORE-TEX Pro 3 layer fabrics.


Versatile high performance designs for diverse activities and conditions.


Versatile: high performance for diverse activities and conditions.


High performance weather protection and materials, emphasizing versatility for multiple activities.

Arcteryx Mens Beta AR Pant Black

Hover over an icon to view more ...

Where to start? Well if you want a pair of lightweight, low bulk, waterproof over trousers then look no further. The Arc’teryx Beta AR pants are a beautiful example of what waterproof over trousers should be. Perfect for 4 season, all-round use in outdoor activities such as skiing, walking and mountaineering.

Looking at the construction you can see that Arcteryx have used two different fabrics in their complex hybrid panelling. The main bulk of the pants are made using N40r-X GORE-TEX® Pro 3L whilst the areas that take more battering, such as the seat, knees and lower legs, use a thicker denier N80p-X GORE-TEX® 3L fabric.

Breaking down the code:

N = Nylon / Number = Denier / r=ripstop, p = plain-weave / X= exceptional durability-to-weight ratio / GORE-TEX® Pro = Membrane / 3L= 3 Layer fabric

For added durability around the instep you get Schoeller Keprotec™ patches for reassuring protection against boot damage, crampons and skis. Made from high tensile aramide fibres, this stuff is designed to take a battering and will last for years. The elasitacted hems feature internal Cordura® Powdercuffs™ and a bootlace hooks for extra protection during snowy alpine days.

Arc’teryx pioneered the industry’s Watertight™ zippers which seal out the nasty weather, on the Beta AR Pants you will find these on the ¾ length side zips, pockets and fly. Arcteryx have used 3/4 length zips so that they don't interfere with a climbing harness or rucksack hipbelt whilst still allowing full and easy access. All the seams have a 1.6mm micro seam allowance and Tiny Gore® (16mm) seam tape in order to reduce bulk and weight whilst improving overall breathability; thinner seam tape equals less weight plus a larger area of breathable fabric.

The fit of these trousers come under the Arc’terx “Athletic Fit”design, which is basically their standard fit. The complex patterning of the Beta AR pants allows for an exceptional articulated fit, providing a great range of movement and means less bulk by eliminating any excess fabric. The Beta AR Pants should have enough room underneath for a lightweight midlayer. Finally for a secure fit around the waist Arc'teryx have included an integrated webbing belt for easy adjustment.

For exact measurements refer to the Link provided in the Sizing Information section.

  • Waterproof
  • Breathable
  • Lightweight
  • Durable
  • Micro-seam allowance (1.6 mm) reduces bulk and weight
  • DWR finish (Durable Water Repellent) helps repel water from fabric surface
  • GORE-TEX® three-layer construction
  • Tiny GORE® seam tape (13 mm)
  • Articulated knees and seat
  • e3D Ergonomic 3-Dimensional patterning for enhanced comfort and mobility
  • Gusseted crotch
  • Athletic fit for a slimmer more flattering profile
  • WaterTight™ external zippers
  • Molded zipper garages
  • Side zippers stop below harness/ hipbelt area
  • WaterTight™ 3/4 length leg zippers
  • Note: Our WaterTight™ zippers are highly water resistant, but not waterproof. We do not recommend keeping items in your pockets that may be damaged by moisture
  • Front fly with snap closure
  • Adjustable pant cuff drawcord
  • Adjustable webbing belt
  • Hip stash pocket
  • Reinforcements
  • Keprotec™ instep patches provide superior protection against damage by boots, crampons and ski edges
  • Reinforced knees, seat and lower legs
  • Powdercuff™, with elastic and lace hook, keeps snow out

Season : Sale

Weight : 0KG

Sizing Information

Arc'teryx Men's Legwear

Sizing refers to your body size, not the size of the product. Pant inseam, length of actual garment.

Size Waist Hip Short Regular Long
XS 29" 36" 30 ½ " 32 ½ " 35 ⅓ "
S 31" 38" 30 ½ " 32 ½ " 35 ⅓ "
M 33" 40" 30 ½ " 32 ½ " 35 ⅓ "
L 36" 43" 31 " 33 " 36 "
XL 39.5" 46.5" 31 ⅛ " 33 ⅛ " 36 ⅛ "
XXL 43" 50" 32 ⅛ " 33 ⅛ " 37 ⅛ "
Size Waist Hip Short Regular Long
XS 74 cm 92 cm 77 cm 82 cm 89.5 cm
S 79 cm 97 cm 77 cm 82 cm 89.5 cm
M 84 cm 102 cm 77 cm 82 cm 89.5 cm
L 92 cm 110 cm 79 cm 84 cm 91.5 cm
XL 100 cm 118 cm 81 cm 86 cm 93.5 cm
XXL 110 cm 128 cm 82 cm 87 cm 94.5 cm

Next to Skin Fit: Cut snug to the body through the entire garment to enhance moisture management and thermal efficiency.

Slim Fit: Cut slim to the body through chest, waist, hip and thigh for a low profile fit.

Regular Fit: Cut comfortably from the body through bust/chest, waist, hip and thigh for a classic fit.

Relaxed Fit: Cut loosely through the waist, hip, and thigh for a casual fit.


Measure around your chest/bust, holding the measuring tape under your armpit.


Measure around your waist at the narrowest part.


From a standing position, measure from your crotch to your ankle.


With your arms in a slightly bent position, measure from the centre of the back of your neck, along the length of your arm, to the wrist.


Measure around your hips at the widest part.

Technical Information

Weight: 515g


N80p-X GORE-TEX® Pro 3L

N40r-X GORE-TEX® Pro 3L


Arc'teryx GORE-TEX® Guide


Care & Advice

Care and maintenance

To keep your outdoor clothing and equipment in tip top condition and performing to its maximum we recommend the use of Nikwax products. We have been using Nikwax products since day one (26th March 1986) and have found them to be totally reliable, dependable and effective. Today’s Nikwax treatments contain environmentally friendly elastic water-repellent polymers that bond to fabric fibres, leaving the spaces between open and breathable. These stretchy polymers are able to stretch and move with the fabric so they stay put for longer and work better.

Nikwax treatments will not change the look or feel of the fabric and they are all water based, environmentally safe, non-flammable and contain no nasty Fluorocarbons. Nikwax products can be used to clean, re-proof and revitalise all your outdoor technical clothing and equipment.

Waterproof breathable clothing has a durable water-repellent (DWR) finish applied to the face fabric during the manufacturing process. The DWR forces water to bead up and roll off the surface therefore preventing the fabric from absorbing moisture. If the outside of your jacket is soaked in a layer of cold water, the warm damp air within can’t escape and will condense on the inside. This makes the jacket feel cold clammy and can make you think that it’s leaking. The DWR finish is not permanent and needs to be maintained and revitalised to optimise performance.

This three layer waterproof jacket should be cleaned regularly with Nikwax Tech Wash; I wash my jacket about once a month, or more often if it gets really filthy. Regular washing with Tech Wash will maintain the DWR for longer and remove salts and oils that can contaminate the fabric, and it will keep your lovely jacket clean and smelling fresh. Washing can be done in a machine according to the manufacturers care guidelines (on the internal label). First clean out any detergent and conditioner residue from the machine dispenser and then add the required amount of Tech Wash and away you go. Hand washing is also suitable but be sure to rinse the garment well.

When you notice that rain/water is no longer beading up and rolling off it’s time to re-proof. Nikwax TX Direct will re-instate a long lasting DWR to completely rejuvenate your jacket. Re-proofing can also be done in the machine once a garment has been washed. Just add the TX-Direct and use the same programme you used for washing. You can also use the spray-on product on a damp garment that has just been washed.

You wouldn’t buy a Ferrari and never have it serviced, so make sure you regularly wash and re-proof your quality kit.

  • 4

    Reviewed by Maurice,  On 29/12/2017 12:50:55

    Lovely pair of all-round trousers for ski-touring. The only thing missing, is a pair of gaiter loops, especially at that price. Arcteryx is the one brand that offers tall sizes for the tall athlete. Trekitt makes ordering online easy.
    YES Maurice would recommend this item
  • 5

    Reviewed by Trevor Solway,  On 28/04/2018 17:46:35

    I am a keen adventurer who is often facing down extreme wet, cold and windy weather conditions whilst on my treks. I needed some gear that I could rely on 100%. These pants are totally amazing. I feel like I am in a suit of armour and totally protected from the elements. Arc'teryx have clearly done their homework. I had previously purchased an Arc'teryx Theta AR Gortex Jacket. I was so impressed with that product that I immediately went to the Arc'teryx catalogue for some pants. I ran comparisons with many other brands, but the overall quality and design to me was unmatched. They are a little noisy to walk in, but the trade-off is the security and confidence that comes from being dry and warm when you need it most, particularly in remote regions. There is a lot of attention to detail. Yes, they cost a lot of money, but I firmly believe they are worth every bit of what I paid. I definitely recommend them. Like most of my gear, I bought from Trekitt. I have always found their advice and service excellent. Many thanks
    YES Trevor Solway would recommend this item
  • Write a review

    Review This Item

    As rated by 2 Customers

    What do you think of Arcteryx Mens Beta AR Pant Black?

    • Your Forename
    • Your Email
    • How would you rate it?
    • Would You Recomend this product?
    • Yes: No:
    • Let others know your opinion.
    • Submit Review
    Coming Soon

    This product will be available very soon. Want to be the first to know when it arrives? Simply enter your email address below and we will notify you as soon as the stock is on the system


    Thanks for choosing this item ...

    Arcteryx Mens Beta AR Pant Black

    Would you like to see the special offer we have for you?



    Excellent customer service. Really detailed easy to understand product descriptions on the Trekitt website, and gear reviews on the Trekitt YouTube channel made it so easy to choose the right backpack for me.
    Emily - May 2020
    Amazing service! Very helpful in regards sizing and what most matched my needs, despite this being done over the internet. YouTube videos of products being examined are very useful also. Would definitely use again, very fast and efficient delivery. Brilliant! Highly recommended!
    David R - April 2020
    Highly recommend. I usually go to the shop in Hereford as staff are alwasy very helpful and knowledgeable. So this was the first time I have purchased online and the service was just as good as the shop.
    Grizzy - April 2020


    Read More Reviews

    Need some help?
    To improve your shopping experience today and in the future, this site uses cookies.
    I Understand