It has been 15 years since crux launched its AK range of rucksacks. At the time, the clean lines were seen as brutally minimalist, but the real appeal lay in the nakedly robust Kevlar fabric that hid a deceptively light and remarkably comfortable rucksack. But the streamlined design wasn’t just a superficial set of aesthetics. Simplicity was engineered throughout: a body made from a single piece of fabric, minimizing seams and weight; an ultralight frame developed by crux from tent-pole technology for increased rigidity; and a low-profile contoured and moulded back panel. And of course the absence of anything and everything superfluous – after all, this was an out and out climbing sack.
Today, the new, third-generation AK rucksacks are functionally and visually the same product. Not so obvious are the engineering and material changes beneath the skin, or rather, Kevlar. The fabric itself has taken steroids, with the Kevlar content boosted from 28% to 40%. All the seams are fully welded, which – allied with a roll-top closure under the hood – renders them completely waterproof. The alloy frame has been replaced by a titanium one; this is slightly lighter, with the added benefit of being malleable to fine-tune the shape. All the external features are literally unchanged.
There are five models in the AK range: AK37, AK47, AK47-X, AK57 and AK70.
The AK47 was the first of the AK sacks to be launched and is our most iconic product, in part due to the accidental coincidence of its name. It has a fixed lid, which creates a better seal against bad weather. This makes it ideal for Scottish winter climbing. The fully removable Z compression straps allow a mat or skis to be strapped to the sides. The tool toggles will accommodate a wide variety of axes, from classic mountaineering piolets through to modern adzeless and hammerless tools. Ski slots and wand pockets complete the picture.
Internally, the AK47 has a single-piece, removable titanium frame. This frame provides lateral rigidity, which is crucial when carrying nearly 50 litres of climbing hardware over long distances. It is also available in three back lengths. Size 1 is designed to fit those up to 5’7. Size 2: 5’7’ to 5’11. Size 3: 6’ and above.
The AK47-X is the AK47 with a removable and extendable lid. It is designed primarily for the alpine market, as its load-carrying options are more versatile. It is identical to the AK47 in all other respects and is likewise available in three back lengths.
The AK57 is a larger version of the AK47-X. It is designed for lightweight expeditions or long alpine-style routes in cold environments, where bulky down gear necessitates a bigger sack. The AK57 is available in three back lengths.
The AK37 is the smallest in the range and is effectively a scaled-down version of the 47. Apart from its smaller capacity, the only other difference is that the 37 has two removable stays rather than a full frame. The fixed padded hip belt, which has the capacity to add gear loops if desired, is the same as on the larger models. The AK37 is currently only available in a single, standard back length, but a long option is being added in 2017.
The AK70 is a rare beast: a 70-litre expedition sack that is genuinely lightweight and robust. It was designed for high-altitude climbing but has also become very popular with long-distance backpackers. This is due above all to its unique, dual-wrap hip belt. While being both unobtrusive and light, it is able to effectively transfer heavy loads onto the wearer’s hips. Crux doesn’t pretend that the AK70 makes carrying heavy loads easy or fun, but the dual-wrap hip belt undoubtedly adds a significant degree of comfort in such situations. The AK70 is available in three back lengths. It has a removable and extendable lid, and retains the same feature set as the other AK models.