Arc'teryx Alpha FL 45

Shortly after declaring my undying love for the Crux AK50, the Alpha FL arrived and made me happy. It has all the characteristics that endeared the AK50 to me, but in a lighter weight, modern package.

Arc’teryx Alpha FL 45

Price: £150
Weight: 650g

weight, durability, simplicity, innovation

Materials and Construction

Outdoor fabrics are getting lighter and stronger. The Alpha FL range is made from N400-AC2, an air and water impermeable fabric that combined with the rolltop closure effectively transforms the pack into a drybag with straps – not a bad idea for Scotland. It feels light and flimsy but has coped with all manner of sharp and poky things, and being dragged across rock has had no effect (it’s just a bit dirtier). The base panel is made from a thicker weight of the fabric. To maintain the waterproof integrity the few seams that exist are internally taped which also adds to their strength. The inner white coating makes it easy to find small items. A basic HDPE foam back panel is bonded to the inside to protect against pointy pack contents and offer a modicum of structure. Despite the name, the main pack body has a capacity of 33 litres, only extending to 45 litres when the rolltop extension collar is deployed. The concept behind this break with normal naming convention (Alpha FL 33 would make more sense) lies in the intended use – climbers will typically load a rucksack to maximum capacity for the walk into the mountains, then unpack things like harness, helmet and protection before compressing the pack down to ‘climbing size’ for the route. This is when the pack needs to be most stable and predictable, and a more conventional drawcord closure comes into play here, tightening down onto top of the rolled top. You’ll notice a lack of lid – I initially missed a big top pocket to stow quick-access things like gloves and hat, but the compartment formed by the spindrift collar between drawcord and rolltop closure works nicely to fulfil this function. The shoulder straps appear thin and incapable of offering any form of comfort, but the high density foam works surprisingly well, and doesn’t seem to absorb moisture excessively. Still, as the waist belt is just 40mm webbing you won’t want to carry heavy loads any huge distance.

There aren’t many features (which is how I like it) but there are some nice touches that reflect the effort and user-testing that has gone into the design. Firstly – the ice tool securing mechanism. The loop of webbing that seems to be featured on everything from hydration packs to 120 litre expedition rucksacks is replaced by sexy metal toggles that thread through the hole in the head of the axe, with the shaft secured underneath the top of the shockcord lashing system aided by webbing tabs. It’s simple, and it really works. This simple web of shockcord is great for stuffing items such as midlayers, crampons or waterproofs (perhaps not at the same time) showing that there’s no need for anything more complex. Just above this is a small zipped pocket with spring clip on a length of webbing – this is large enough for a small first aid kit, keys or electronics like a GPS. Further up is the long rope strap – plenty long enough to stretch over the extended collar – with the excess rolled up and secured with a little Velcro strap affixed to the end of the strap. It’s brilliant. The other key hardware is the cordlock on the drawcord closure, which is a captive, one-handed operation design that works well with gloves on. Two tiny webbing loops on each side offer the ability to thread compression straps or lash items to the side of the pack. I’ve not seen the need yet.

In the introduction to my AK50 review I suggested that “mountaineers look for a rucksack able to cope with hauling in a heavy load of hardware in relative comfort, that’ll then cinch down and remain unobtrusive and rock-resistant during the climb”. Possessing these characteristics and more in an innovative 650g package, the Arc’teryx Alpha FL 45 has replaced the Crux AK50 as my mountaineering pack of choice. How oddly frustrating.
What do you reckon? Prefer the AK50? Let us know at the forum

Enjoyed this article or find Walkhighlands useful?

Please consider setting up a direct debit donation to support the continued maintenance and updates to Walkhighlands.

Share on 

Walking can be dangerous and is done entirely at your own risk. Information is provided free of charge; it is each walker's responsibility to check it and navigate using a map and compass.