Crux AK37 Rucksack

Crux AK37 Rucksack

Regular Price: £229.00

Special Price £205.00 save 10%

Incl. 20% Tax

Availability: Out of stock

Lightweight, incredibly durable and stripped right down to the essential features, the Crux AK37 is a near-perfect alpine climbing rucksack. Rather than splashing out on fancy back systems and unnecessary features, Crux have focused on an elegantly restrained design built from premium materials.



Crux AK37 Climbing Rucksack

Lightweight, incredibly durable and stripped right down to the essential features, the Crux AK37 is a near-perfect alpine climbing rucksack. Rather than splashing out on fancy back systems and unnecessary features, Crux have focused on an elegantly restrained design built from premium materials. The fabric contains a whopping 40% Kevlar, giving it a huge strength to weight ratio, and it's put together with all welded seams, maximising water-resistance.

Tubular titanium back supports give the pack structure and make heavy loads more comfortable to carry, but hese are removable if you really want to save weight.

  • Weight: 1040g
  • Capacity: 37 litres
  • External lid pocket with welded seams
  • Side compression straps – quick and easy to fit or remove
  • Oversized back haul loop – easy to grab and clip
  • Top compression strap
  • 4mm Tendon climbing accessory draw cord
  • 40 mm webbing waist-belt with low-profile full-sized hip-fins
  • Internal sleeve for hydration bladder
  • Two ice-axe holders with titanium keepers
  • Stretch wand pockets
  • Available in 2 different back lengths
  • Fabric: 240g/m2, 40% Kevlar, 60% Cordura
  • Removable Frame: 7mm tubular titanium


Activities Aid Climbing, Alpine Climbing, Climbing, Expedition, Ice Climbing, Mixed Climbing, Mountaineering, Trad Climbing, Winter Climbing
Weight 1040g
Brand Crux
Gender Unisex
Size Guide

Crux Logo


The AK47AK47-XAK57 and AK70 come in three sizes, based on back length (see table and diagram below).

The AK37AX45, AX50, RK40 and RK50 come in two sizes, R (regular) and L (long) (see table and diagram below)

The AX30AX35, AX40 and RK30 come in one back length only, which is equivalent to size R.

SizeBack LengthTypical Height Range
1 45cm 160-170cm
R 48cm 155-175cm
2 50cm 170-180cm
L 55cm 175-185cm
3 60cm 180-190cm

Size 1 is optimised for women but fits small men too.

Crux Rucksack Size Back Measurement



We try to keep the site updated with products that are in stock and despatch within 1-2 working days (Mon-Fri). Occasionally items ordered may be out of stock. If this should happen we will contact you to let you know when we will be able to despatch your order.

Please note that all deliveries are made between 08.00 and 18.00 Monday to Friday and may require a signature.

Free Delivery

Orders are typically despatched with Royal Mail Tracked 48. Please note that this is a guideline only as a different delivery method may be used depending on the size/weight of your order – if you would like any more information on your delivery please contact us.

Click and Collect

At checkout, please enter your billing address as the shipping address, then choose Click and Collect as your Shipping Method. Click and Collect items are available to pick up Monday – Friday, 9:00 am – 5:00 pm (excluding Bank Holidays), one working day after your order is confirmed.

When your item is ready to collect, you will receive a confirmation email; please either bring a print out of this or show us the email on your phone. You will also need to bring a form of ID which shows the billing address for your order.

Please collect from the back door at the end of Outside's customer car park:

Outside Ltd
Main Street
S32 1BB

Online Only Range

“Online only” products are not available for immediate despatch but you will still normally receive these items within 5-7 days of placing an order. If there are likely to be any further delays we will of course be in touch. These products cannot be purchased in our stores.

Next Day Delivery - £5.95 - this service has been suspended until further notice due to the Coronavirus crisis

Redirection of your order once despatched

We regret to say that we are unable to change the address or postcode on a parcel once it has been despatched. We therefore recommend that you check your delivery address and postcode carefully before completing the order as this will not be checked by us before despatch. We also recommend that orders are sent to an address where someone will be available all day to receive the parcel, e.g. a work address.

European and International Delivery 

There may be delays to international deliveries due to the Coronoavirus crisis. Please see our update here for further information: Outside Update

  • Orders weighing 2kgs and under, going to European countries will cost £9.95.
  • Orders weighing 2kgs and under, going to other international destinations will cost £11.95.

Orders over 2kgs or bulky orders may be more expensive to post - we will contact you before we process your order if this is the case. The majority of our International orders are sent with Royal Mail's International Signed or Tracked services, which will then be passed to the postal service of your country for onward delivery.

BFPO Delivery

We are happy to deliver most items to BFPO addresses. If your location means that your purchase is VAT-exempt, we are happy to deduct the VAT from your order before shipping. Please make sure that you include your BFPO number in the Postcode field on your order so we can verify the VAT-exemption.

When filling in your details on the website, please enter your card holder address as normal, and the delivery address in the following format:

First Name/Last Name   

Your name/rank

Address Line 1

Your appointment or unit


Your barracks or PO Box no.


Your BFPO no.


Choose BFPO if you are VAT-exempt, United Kingdom if you are not

Delivery is free to BFPO addresses, however we may be unable to ship certain items due to their size, weight or value. We will contact you if this is the case. If you have any problems or queries, please contact us.


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