Free Standard Shipping for Orders Over $50
Home Page

Detail Images

Current Color

Arc'teryx Alpha FL 45L Backpack

25% Off
sale $209.25 $279.00

Select a Size

  • Reg
    - Unavailable

Select a Color

  • Cardinal - Unavailable
  • Black - Unavailable

Free Shipping on orders over $50*

Alpha FL 45L Backpack

The ultralight and highly weather-resistant Arc'teryx Alpha FL 45 Backpack is designed to help you move quickly through rugged terrain whether you're on a light alpine mission, crushing ice and rock climbing, or putting in technical ski mountaineering lines.

Arc'teryx made the Alpha FL from lightweight but bomber ripstop fabrics to withstand the rigors of ice and granite without slowing you down. To keep your back and shoulders comfortable, the AC2 suspension system offers load support with minimal weight, while compression straps help you manage your load for better balance in tricky spots. The Alpha FL is also fitted with an expandable drawcord collar for additional capacity on a minimalist overnight trip. External attachment points can be used to hold skis or a sleeping pad, and a front panel bungee attachment stashes crampons or an extra layer so you don't have to stop any unpack every time you move from flat ground to steep snow or ice. The webbing hip belt is lighter than padded belts and fits more comfortably under a harness, and thermoformed shoulder straps and a rigid formed backpanel provide support and structure while still offering a comfortable fit.

  • Lightweight backpack built for alpinism and ski mountaineering
  • Water-treated fabrics and fully sealed seams for weather protection
  • WaterTight zippers and roll-top closure for added protection
  • AC2 suspension system offers support with minimum weight
  • External attachments for ice axes and crampons
  • Item #ARC00HS

N400r-AC2 nylon 6 ripstop, N100mr-HT nylon mini ripstop, N70r-HT nylon, HyPUR-cel foam, [back panel] HD 80 polyethylene foam
45L (2746cu in)
AC2 system
Shoulder Straps
400D AC² nylon ripstop, Burly Double Weave foam, Hypercell foam
Waist Belt
yes, 40mm nylon webbing
1 main compartment, 1 security zip
Gear Loops
Ice Axe Carry
Claimed Weight
1lb 7oz
Recommended Use
alpine & expedition, climbing
Manufacturer Warranty

Tech Specs

What do you think about this product?


>Rating: 5

This bag does it all

I've put it through the wringer

Many of the other reviews brought up phenomenal points. I have owned this bag for nearly two years and it is my most used pack aside from my patagonia ascensionist 30l and 45l. The difference between the three packs is the Alpha FL45 still looks nearly brand new. The N400-AC fabric has been literally bomb proof for me. It has held up to a few falls skiing and climbing while loaded with screws and crampons and still keeps going. I only had one nasty fall that ripped an axe off of the pack however my retention lanyards made that a non issue at the time. The only time I have had issues with moisture in the pack is with the pack expanded to the 45l capacity in heavy rain... this is a non issue for me as I always use waterproof stuff sacks to compartmentalize my pack. The only things that aren't tend to be gear I may need on climbs and even still we have jacket pockets. The hip belt is perfect and there if I need it, the load is light enough it is a non issue for me... Far from the stereotypical 65-100lb military ruck. Like others have mentioned the pack was not designed to carry skis... I however have had zero issues mounting skis in an A frame configuration and long term durability of the side loops is fine. I ended up using two dyneema quickdraws and it worked decent on the fly. Long term I made some doubled over elastic straps at 1/2" with fastex buckles that held the skis phenomenally utilizing the side retention loops. Pair that with a voile strap to keep the top of the skis taut and it won't go anywhere on you. The straps doubled as added retention for the ice axes as well. If you always use the rule one is none, two is one you will be fine with this pack or anything else for the most part. Double up on water protection as well as secondary gear retention and this pack surely will not let you down on long excursions. Pros: Durable, lightweight, capacity, waterproof, articulates well, exterior rigging options Cons: Price compared to competitors packs, lack of load lifter straps " partially gives better articulation on steep ice however shifting weight while skiing is something I had to get used to".

>Rating: 5

Worked great for canyoneering

I've used it once or twice and have initial impressions

I got this pack for my husband and the 30L for myself for our canyoneering trip down in Southern Utah. I got the 45L for my husband and I actually think the larger size was a better option, especially if you're going to be carrying one of the ropes. I did carry a 100ft rope, a wet suit, snacks, harness with gear on it, and water. It was a really tight fit, but worked. The minimal hip belt is perfect to have when wearing your harness. It doesn't get in the way but still is nice to have when hiking up the canyon before rappelling down. We were in water where we couldn't touch and the packs were completely waterproof. This was really nice because not only did our stuff inside stay dry, they weren't saturated at the end of the rappels so they weren't any heavier. They also floated which was great. They're super lightweight and nice and narrow. We had to squeeze through some tight spots and they didn't hinder us at all.

>Rating: 5

Beauty in Simplicity

I've used it several times

This bag is simple, straight-forward, and bomber. It only has one compartment, but if you pack well, it's not an issue. I love the expandable drawstring system at the top, too. I was pleasantly surprised by how comfortable it was when weighed down with gear, as well as how balanced it felt when walking. Overall an awesome, simple pack for any winter adventures that will last for years. 10/10 would recommend.

>Rating: 5

The best

I've put it through the wringer

I love this pack and everything about it. I have used this pack for both technical purposes (i.e., climbing and hiking) as well as just basic commuter/daily purposes and I find it works great for both. However, it clearly is designed, and excels the most, in the alpine environment. Pros: (1) The pack is amazingly lightweight for its size (there is a caveat to the size I will mention later). (2) It is incredibly durable and water proof. I personally have yet to tear a hole into this pack or managed to have any water permeate it whatsoever. (3) Simplistic design with just enough support in its frame and straps (4) The design allows it to hold tightly to your body, which is incredibly important in a pack while climbing. (5) Easy to manipulate (i.e., open the main and external compartments, put on/take off, adjust straps, unclip waistbelt) in the freezing cold while wearing multiple layers of gloves. Hell, although I haven’t tried, you could probably do everything you need to even with mittens on. (6) Ice axe/tool attachments are easier to use than traditional attachments (7) Crampon straps work great. I thought my crampons would have cut these by now, but I have yet to have any issues. Also, you can use the straps for other things you need to attach on the outside (e.g., helmet, belay jacket) (8) I actually find the key hook in the external pocket quite useful most of the time. That said, I am not carrying my house keys on me for big alpine objectives and haven’t found a use for it then. (9) The external attachment points on the Alpha FL 45 (do not exist on the 30L model) are very useful, particularly for attaching boots for approaches. Cons: (1) Expensive, but it find it is worth it (2) The size is a bit deceiving, as the size in the name of the product is actually the size with the roll top fully expanded.

>Rating: 5

Best skimo backpack

I've put it through the wringer

The simplicity is the greatest thing about this pack. After two seasons I've used this pack for a litany of missions, but ski mountaineering has been the best application. Pack intelligently and there's nothing better. The white interior makes a bigger difference than you'd think and the shoulder straps are way more comfortable than they should be. I couldn't be happier.


What ski pant are you rocking?

>Rating: 4

Lightweight, but doesn't carry skis well

I've put it through the wringer

I have mixed feelings about the Arc'teryx Alpha FL 45 backpack. The Pluses: * It is crazy light! The lack of padding on the waist belt and should straps doesn't affect the comfort. * The material is bomber-strong. Arc'teryx-strong! * It rides close to my back which gives it an extremely balanced feel. The balance is enhanced due to its tall-and-skinny profile. The Neutrals: * There is only one compartment. Duh! That'€™s due to its weight-saving design. I use three ultralight stuff sacks to organize my gear within the pack which worked well. However, I now know I would prefer one or two simple compartments even if it adds a little weight. * There isn't a dedicated avalanche rescue gear compartment--again, for weight savings. I had a friend make a small (light) sack to keep my three avy items together. On my next pack, however, I'll return to a dedicated compartment. * It's 35 liters and 45 liters when the collar is extended. I knew that when I purchased it and am pleased with its size, but just in case YOU are thinking it is 45 liters... The Minuses: * It doesn't carry skis well. This is a big issue for me. Before buying the pack from, I wrote Arc'teryx asking if they sold ski straps. They told me to use any strap. But it isn't so easy: the loops on the back of the pack have tiny loops (2-3 mm), so I had to tie into the loops using 2-3 mm cord. The loops on the sides of the pack were also quite small. I had four straps made from 5/8-inch€ webbing. Although time consuming, when I was done the straps were very functional. However, the third time I mounted my skis, one of the backpack's side loops pulled out from the stitching (and FWIW, I was carrying ridiculously light Dynafit Denali skis). Deep in the French Alps, I had to puncture the pack with my knife and repair the loop with a zip tie. graciously warrantied the pack and I think it was a manufacturing defect rather than a design defect (the other three straps held up to repeated ski carrying), but the bottom line is, between the complexities of making the straps and the failure of a pack loop, I don't recommend this pack to carry skis. * The ice axe thingies (the T's on the elasitc) are a good idea, but they don't cover axe's pick and aren't very secure (I lost an axe...). * Occasionally my scapulas (aka shoulder blades) are slightly uncomfortable due to the lack of padding on the back. This is minor. My Use: I used the Arc'teryx Alpha FL 45 backpack for 30+ days of backcountry skiing, including a six-day hut trip in Europe. I've owned a half-dozen different ski touring backpacks over the last 20 years. My most recent backpack before this was a Black Diamond Anarchist.


Solid review and helped me decide on purchasing, thanks! Also, clever ski attachment strap rig you did there. I could be wrong but I think they intended the middle lash point (with the larger aperture) to be the one used for the ski straps. Using a single piece of flat webbing, with a ladder lock to tighten it, this creates a zig-zag configuration going from the top lash point near your body, to the middle point on the pack's back, then back to the lower point near your body. Kind of a mirror image of what you'd find OEM on an Osprey Talon. Seems pretty stable so far, if the bindings are properly snared, but I haven't field tested. Time will tell. Cheers!

I appreciate the comment. I was about to buy one of these but the size comment is what swayed me elsewhere. I wish they'd market the size more like Deuter using a plus sign (e.g. 35+10).

You can actually just stick a ski strip through the loops. In this picture, the strap would go through the right loop, not the left one. Fits snuggly. Not sure what the problem with ice axes is. When I have my axes on the pack, I put the picks underneath the bungee cord to keep them from moving at all. Have never lost anything, and this pack has taken my to Chamonix, Patagonia, Cascades, Canada. Just saying ;)