Overnight winter alpine pack size

I'm going to be spending overnight winter alpine trips in a tent for the first time this season, so I need to update my pack to carry the extra gear. I am considering the BD Mission 55 and the Osprey Mutant 52, but I am not sure if they are big enough for my purposes.

For the past few years, I've been using my BD Speed 40 for hut-based overnights, and it was perfect for carrying everything on the hike in, and then for paring down for the climb. I won't list every piece of gear I carry, but it's a basic setup for technical winter mountaineering, including layers up to a down belay jacket, single rack of cams, technical tools, one half rope, etc. The speed was usually packed almost to the brim, but with not a thing dangling outside except the sharp stuff.

This year, I'll be adding a tent (Rab Latok Mountain 2), sleeping bag (Marmot Lithium), and sleeping pad (NeoAir XTherm). I've typically only done overnights in the past, but I'd like to consider a pack that I might push to 2-3 nights for potential future endeavors. I'm hoping for a bag that I can use the way I have used the Speed 40. Fully packed to base camp, then stripped down to the essentials for the climb. 

I'm considering the BD Mission 55 and Osprey Mutant 52 for this purpose. Any preferences between these two, or recommendations of other options to consider? Or should I be looking at something more like 60+? My concern is that once a pack gets that big, it's hard to pare it down for the technical part of the mission, and I'd rather avoid a two pack setup if at all possible.

As always, thanks for any input or advice!

I think it's going to be a challenge to make a 50-55L pack to carry all that gear well, and then still be quite comfortable, and climb well. Maybe for one overnighter, but for two or three? Considering all the extra food you're also going to bring I'd opt for a load hauler and a climbing pack. But that's me. 

Edit: assuming you're going  to climb from a base camp. If we're talking alpine style you're going to have to make do either way ;)

Awhile ago Osprey had the mutant line of packs alongside another line of climbing packs that was a bit more robust in both weight and carry comfort. I don't remember the name, but I've the got the 52L version of the other pack.

My feeling is that the 52L osprey is barely big enough for a winter kit for 1 or 2 nights. But this will depend on a number of factors: how much load carry comfort you need, how light/small your current set up is, how big you are (I'm taller, so my clothes and sleeping bag both take up more space), your tolerance for strapping stuff to the outside of your bag, your desire to hike in a helmet and/or harness, etc. 

To me, 50L is the boundary for a pack that climbs well on route. If the climbing is easier or it's an integrale ascent and required, then it's fine. But if I can leave the big pack at camp, I'm more apt to take a summit pack since the harness, helmet, rack, rope, tools, etc. will all be in use anyway and not in the pack. I use a summit pack akin to the old REI flash. I know Blue Ice has a similar offering these days, I believe camp has something in that category, etc.

I used the Mutant 52 for a three night glacier climb on Rainier a few years back. Not exactly the same types of gear, but probably similar bulk/weight. Pack was stuffed full, with rope draped on the outside and foam pad under the lid. Thought it carried well, though. I've also used it for a three night backpacking/climbing trip, but did throw a small pack (Blue Ice Dragonfly 25) in the bottom of my pack for the summit climb. The Mutant will slim down pretty well, especially with the brain removed, but it's still a fairly large frame, so it just depends whether that will impact your climbing. I would 100% recommend going into stores and putting all their pack testing weights in the pack, and wearing it around the store for a bit - for whatever reason my back likes the Mutant 52, but cannot deal with the Variant 52, or most other packs that I tried with the weight in it.

Try and fit all of your stuff into the Speed 40 and see if it works.  I've used that exact pack (and also the Speed 30) for quite a few winter overnights including technical climbing.  Yes, it will be tight, but then you have a smaller and lighter pack on route.  If that doesn't work, 50 liters will surely be enough.

I don't think there is any need to go bigger than 50L, unless you are expedition climbing, or actively choosing to bring a bunch of camp luxuries (which can be awesome, depending on the situation).

I agree with Kyle... 50L at the most. Lots of people will argue otherwise but just look at what actually gets used on 7-10 day climbs in the greater ranges by top climbers, they are fitting it all into 50-55Ls so the problem is dialing in your systems, not getting a bigger pack. I think the big question is... will you be overnighting on climbing routes or base camping and doing one day routes from camp? If base camping you can be a bit of a junk show with your approach pack (stuff strapped to the outside, though ideally nothing dangling) in favor of a smaller pack for climbing. If camping on route you need your pack to handle a bigger load while climbing (remember it will be slimmed down a little from the rack/rope/etc being out and on your harness). 

You also have to consider precip/climate, both the speed and mutant are great for bigger loads (I use the speed 50 for bigger overnight loads) but they are not waterproof and the big waist strap isn't great for climbing with. I use the Arc'teryx Alpha FL 40L when I can fit everything, especially if the weather is crap, because it has a roll top and waterproof fabric that is clutch at belays when its spindrifting. People will probably talk crap about how much it costs but its been on 3x the climbs as my mission 50 and looks less beat up, add the light-weight, easy to climb with design, etc and its probably worth the extra $$. 

With regards to fitting everything you have to consider your insulation systems. You should expect to wear every single clothing item to bed, except socks and gloves that you're drying out. I typically go with a lighter bag and sleep in puffy pants/jacket. Also, unless you are planning to base camp for several days, then just cram in one tent with your partner and snuggle which saves on insulation and shelter reqs. 

Yeah, the waist belt on the Speed 40 sucks to climb with, luckily it's strippable so I just pop it off when the going gets tough (the webbing portion of the belt stays in place, and that is fine).

It's wild to me how many people recommend the Mutant 38, that thing has a massive comfy hipbelt that is not removable.  I used that pack over a harness on one route and then prompty returned it, I have no idea how people are accessing a rack and avoiding hip blisters with it.

I’m with Kyle and Sam, I see no reason for 50+, especially for a single overnight. 3-4 is tougher due to the provisions, and it really becomes a different case.
 It seems like you should only be adding a pad, bag and half a tent. You said nothing was on the outside but on the way to camp it usually is not a problem to carry the rope on the outside, that alone would free more than enough pack space.

Get dialed in with your partner, don’t carry redundant stuff…

diepj wrote:

I’m with Kyle and Sam, I see no reason for 50+, especially for a single overnight. 3-4 is tougher due to the provisions, and it really becomes a different case.
 It seems like you should only be adding a pad, bag and half a tent. You said nothing was on the outside but on the way to camp it usually is not a problem to carry the rope on the outside, that alone would free more than enough pack space.

Get dialed in with your partner, don’t carry redundant stuff…

Sorry, to be clear, the rope is draped on the outside of the bag on the top, never inside the pack. Crampons and axes also strapped to the outside.

The tent is a single-wall, so it’s not splittable.

My partner and I have been climbing together for the past few winters, so our systems are already pretty dialed. We’re not exactly ultralight, but we don’t carry any redundant equipment.

AaronJ wrote:

The tent is a single-wall, so it’s not splittable.

Understood.  In that case, your partner carries equivalent group gear, like the stove and the tent poles, or something like that.

Earlier this year my partner and I went into The Enchantments early season.  I brought ice climbing gear, a -5 degree bag, a BD Firstlight, and a mixed rock and ice rack.  I used my Speed 40.

I’ll have to give packing everything in the Speed 40 another shot, but I’m having trouble envisioning it. In past years, I’ve usually had it stuffed full with the sleeve pretty well extended, and that’s without the tent/bag/pad. Maybe my gear and clothes aren’t the most packable.

I dug through my photos and found a couple of the gear that I brought on the trip I mentioned, maybe this will help.  The axes and closed cell foam pad were on the outside, the rope of course, and maybe the crampons?  My partner carried the tent, ice screws, and slings (I had the stove, rock gear, and rope, so that's about even).

Pretty stuffed on the way in, but it sure beats trying to climb alpine ice and mixed in a floppy 50L pack.

Kyle, is the grey compression sack your sleeping bag? I am really curious what type of -5 F bag you fit in that pack. My warmest bag is a 15 F 850 fill down, and it feels like it eats up half of a 60 l pack, let alone a 40. I want to do more winter overnight alpine in the future, and dealing with sleeping bag volume is one gear question I have. 

JC - you might want to turn the bag inside out before you stuff it. If there's any weatherproofing on the fabric it's hard to compress.

Aaron - I used to live in Tokyo. Where are you climbing? I climbed Mae Hotakadake and Yarigatake in the Kita Alps.

And, I feel that 4,000 is a big pack for climbing. That's close to 60L. But I've done it. I have a SARC variant but take the plug n' play top of the frame off. No lid. I've climbed more with an Andinista, 1 zipper compressed an no lid. That's supposed to be 3500 ci, which is close to 50L I think.

More important to me is weight. Bulky insulation is not so bad, but weight will really get in your way. 

J C wrote:

Kyle, is the grey compression sack your sleeping bag? I am really curious what type of -5 F bag you fit in that pack. My warmest bag is a 15 F 850 fill down, and it feels like it eats up half of a 60 l pack, let alone a 40. I want to do more winter overnight alpine in the future, and dealing with sleeping bag volume is one gear question I have. 

Yes, the gray compression sack is my sleeping bag.  It is a Rab Neutrino 800 -8F: https://rab.equipment/us/neutrino-800

That compression sack is around 15L 

A 15 degrees down bag should pack down really small.  My shoulder season bag is a 20 degree Feathered Friends bag of some sort, and it goes into a compression sack that is ~8 liters.

The compression sack volumes are fully expanded, so once you cinch it down I bet the actual volume is like 1/2 that or less.

I would recommend the BD Mission 75. It climbs quite well and it pretty light (esp if you skip the vestibule). With the spindrift collar expanded you will easily fit all your gear. It has nice ice ax and crampon carry. It climbs quite well when seconding and is definitely NOT hard to pare it down for climbing -- you don't have to pare it down really, just skip the vestibule all together, maybe snug the compression straps, and it's ready to climb (I never remove the back panel, doesn't seem to matter). It hauls heavy loads on the approach quite well for the weight of the pack. It has become a much more versatile pack than I initially anticipated and it has become a staple for 4 seasons of climbing. I would take it over an Osprey Mutant 52 every time. 

Additionally, I think part of the answer to this question is very dependent on where you will be climbing and how big you are. I use size long sleeping bags and wear size L puffies - this will add a significant amount of volume compared to their smaller siblings. My kit isn't that old (although it's not the very newest tech in layers or UL gear) but my equivalents of the kit Kyle has pictured would never fit into his pack. I think the approaches also are worth considering -- are you skinning uphill for 9 hours to approach? If so I'd take a slightly larger pack with better suspension (i.e. the Mission 75 over the smaller siblings). 

Other packs in my quiver include the Arc'teryx Alpha FL 45 and Crux AK-57. The Crux would work for everything above, I might choose it for objectives with less approach and harder climbing, but honestly it probably wouldn't matter as the Mission 75 is so similar. Straight up the FL 45 would not fit for me in contrast to Sam's experience above. 

Overall, this questions gets asked all the time on the forums and, surprise, everyone has there own opinion. Get a used pack you think might work and try it out, you'll figure out what works for you. 

Linnaeus wrote:

I would recommend the BD Mission 75. It climbs quite well and it pretty light (esp if you skip the vestibule).

I own a Mission 75 and I would not  say it "climbs well" for me (stiff frame, large waist belt, tall overall height, etc.).  I use that pack when I need to haul a week's worth of stuff or more, like on a trip into the Bugaboos, going into base camp in the Cordillera Blanca, or Denali.  I would not want to climb anything remotely steep with that pack on.  Large packs may also encourage overpacking because you can just keep putting stuff in there.  Seems unlikely that a changing a couple layers from Medium to Large requires an additional +35L over the Speed 40.

Haha Kyle, I don't disagree with you because I know from our college days that you are a very reasonable objective guy. However, I think I recall I'm taller than you so that will certainly impact the fit. The M/L is not tall on me (even my wife uses it at 5'7"). I would never lead climb steep ice or mixed with it (or probably wearing any pack), but I've seconded with it and it hasn't ended my day. Or left it at the base of remote ice climbs or summer backcountry multipitch rock routes. 

Every time this question is posed there are lots of different responses likely because of all the wide variables like person size, temperatures, objectives, required kit, willingness to suffer, etc. I normally try not to respond because it is always the same varied responses that depend on the person and their experiences, preferences and mostly subjectivities. Classic YMMV. For this discussion, I have packs in sizes 35L with massive extension collar, 42L, 52L, 57L, 62L, and the Mission 75. The Mission 75 is the same weight and only very slightly larger than the old Arc'Teryx Khamsin 52 and about the same size unextended as the Crux AK 57; they probably would all work about the same in practice but I mostly choose the BD for modern ice tool attachment. 

In the end, people just need to try different packs for their objectives. We all probably interpret the OP's statement "overnight winter alpine trips [sleeping] in a tent" in a different way.  If this is the sole factor keeping someone from completing their objective I would be surprised. 

sign me up in the "use your speed 40" camp, I managed to do multiple 4-5 day trips out of one, for that matter I did a 4 day this fall out of a Mutant 38... which included an almost triple rack, plus lots of extras for unknown conditions...is it ideal? not at all, but neither is a big pack that won't compact as much as you want or a two-pack system...strategic packing is key, the fewer things in stuff sacks the more you can fit, use a loose tent, puffy layers, and anything else flexible to pack all the voids between solid items like the stove and food, put tent poles in by the frame stays of the pack, let the air out of food packaging- if you minimize the packaging of everything  it's surprising how much you can fit in a 40 L

Linnaeus wrote:

Haha Kyle, I don't disagree with you because I know from our college days

Whaaaaaat?  Small world! :)

Every time this question is posed there are lots of different responses likely because of all the wide variables like person size, temperatures, objectives, required kit, willingness to suffer, etc. I normally try not to respond because it is always the same varied responses that depend on the person and their experiences, preferences and mostly subjectivities. Classic YMMV. For this discussion, I have packs in sizes 35L with massive extension collar, 42L, 52L, 57L, 62L, and the Mission 75. The Mission 75 is the same weight and only very slightly larger than the old Arc'Teryx Khamsin 52 and about the same size unextended as the Crux AK 57; they probably would all work about the same in practice but I mostly choose the BD for modern ice tool attachment. 

In the end, people just need to try different packs for their objectives. We all probably interpret the OP's statement "overnight winter alpine trips [sleeping] in a tent" in a different way.  If this is the sole factor keeping someone from completing their objective I would be surprised. 

Definitely can't argue with this!  My only intent was to make sure OP was aware that it's quite possible to fit into a smaller pack IF they desire.  If not, party on!

I've had my mission 55 stuffed full for overnights multiple times and have noticed the right shoulder strap is starting to rip where it connects to the pack body. Maybe i could be more careful but I've also seen two other people with similar BD packs that have the same issue, seems to be a design flaw. Great pack otherwise but this is a deal breaker, wouldn't have bought it if I'd seen that first, can't recommend it.