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What is an Ultralight Backpack? Blast 32 Backpack Blast 32 Backpack (Scotland)

Ultralight backpacks tend to be a lot lighter than more mainstream backpacks with internal or external frames and generally fall under 2 pounds in weight. There are exceptions to this and some UL packs are heavier than two pounds, but it’s a pretty good rule of thumb.

Historically, ultralight backpacks were mostly frameless, but a lot of the UL packs you can buy today come with optional pack stays, which effectively put the “frame back in frameless.” These are aluminum or carbon fiber rods that slide into pockets in the back of the pack and stiffen it up, enabling you to carry heavier 25 to 40 pound loads.  They also transfer more of the pack weight off of your shoulder straps and onto the hip belt.

Gossamer Gear Mariposa Plus Backpack
Gossamer Gear Mariposa Plus Backpack (Vermont-Canada Border)

But I think the thing that sets UL packs apart from other packs is their design, how you pack them, and how you “interact” with them during a backpacking trip. But first, some backpack anatomy:

Most UL packs have the same basic design:

  • A large main compartment
  • A roll top closure, and not a top pocket or floating lid
  • Two side pockets
  • A large open front pocket, often made out of mesh or solid fabric for better durability
  • Lots of attachment points around the perimeter of the pack
Hyperlite Mountain Gear Windrider Southwest (photo courtesy of Mike St. Pierre)
Hyperlite Mountain Gear Windrider Southwest (photo courtesy of Mike St. Pierre)

When you pack a UL backpack (for 3 season use), you put all of the gear you might need during the day into the outside pockets of the pack including water bottles, rain gear, snacks, hat, compass, map, camera, and whatever water purification system you prefer. Everything else gets packed inside the main compartment and is closed off for the rest of the day until you get to camp. Many people who use UL backpacks also store their shelter on the outside of their packs, so they can set it up before they have to open the main compartment of their pack. This helps keep your sleeping bag and clothing dry if you need to set up your shelter in the pouring rain.

By placing everything you might need on the exterior of your pack you can move very quickly during the day, without having to take a lot of breaks to find stuff buried in your pack. The convenience is addicting and I struggle with internal frame packs, where nearly everything you carry is packed inside the backpack and requires longer stops so you can dig it out.

Gossamer Gear G4 Backpack (New Hampshire Appalachian Trail)
Gossamer Gear Backpack (New Hampshire Appalachian Trail)

One of the design elements that I like best about UL packs is the ability to set up ad hoc rigging systems using the external attachment points. It’s very handy if you have a long tent or fishing pole you want to secure to the side of your pack, crocs, a platypus – if you need to carry extra water for a stretch, or a sleeping pad. If you carry an external frame backpack, you also have this kind of flexibility, but I don’t find it that much on internal frame packs, which is a shame, because it really stretches the utility and value for money that you get on packs that can be used in many different ways.

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  1. Good stuff. Suprised you didn't mention fabrics. What's your thoughts on the durability of cuben fiber?

  2. I own a Gossamer Gear Mariposa Plus…Love it. I sectioned hiked the Pen Mar Park to Harper's Ferry portion of the AT with it and saw one other person with the same pack. Like most UL packs one has to be more careful with it than a regular pack. It came out unscathed but on another trip I did get a little wear hole on the back side that I had to repair. They are not meant to be treated roughly. But, helped me get the total pack weight to under 30 pounds.

  3. The general absence of bells and whistles is one of my favorite aspects of UL packs. Back in the day, I was so eager to have a pack with one of those bottom-zipper sleeping bag compartments, but when I finally got one I never used it, realizing that a simple one-pocket design was much more functional for me. When I switched to UL packs, I was initially daunted by the lack of a floating lid, but quickly discovered that I didn't miss it at all. Now I find over-engineered products to be somewhat of a waste. For me, simpler is much better.

  4. What are the bottom of UL packs made from? Something a little stronger/abrasion resistant I hope.

    Hard to tell from pictures because no one ever shows a pack upended.

  5. Jarra– usually the same material as the rest of the bag. Some companies are starting to use more reinforced fabric in certain areas (like the bottom), but if you don't treat the pack like it's made of iron, it's not going to wear out so quickly. My MLD Exodus has over 3000 miles of use, with only a few holes in the mesh pockets. My friend Gary's GG Mariposa, made of lighter silnylon, had over 3000 miles of use before he mostly stopped using it. I haven't tried cuben yet, but these packs aren't made of newspaper. They're more than durable enough for their intended purpose.

  6. I have been using a ULA Circuit backpack. I love it. Both the simplicity of it and how it carries on my body. Even with a full load (which for me is about 26 pounds) I don't have a sore spot anywhere.

  7. Paul – I view fabric selection to be largely irrelevant. It's really the design and way you use them which matters. Cuben, dyneema, and silnylon are the fabrics of the hour, but that will change when something new comes along. To answer your question – cuben is durable, but so are a lot of other fabrics. Thickness is ultimately what matters the most.

  8. I've had to rethink some of this for winter as far as what's in the outside pockets. The following seem to need to migrate inward: water bottles, fuel bottle (if you use alc), gadgets with batteries (phone, camera, flashlight), lunch that you don't want to turn into jawbreakers. Do you want to comment on packing strategies as weather cools down? Some things can wait until I'm in my sleeping bag like the thermos I brew at night. Some foods I choose because they don't turn hard (fig newtons versus granola bars).

  9. I wish I could use a UL pack for winter, but I find that the things I need on the outside need to stay dry or are too heavy or too sharp for mesh. I'm also carrying a much much heavier pack – like 50 pounds, including food, water, fuel (liquid stove), shelter, crampons/snowshoes, ice axe, and so on. Packing everything in one big sack doesn't work either, because you do need to get at things during the day like googles, balaclava, gloves, water, water, water, food, and so forth. I wish there was a decent UL winter pack available that did it all but until then I'm using an alpine style pack from Cold Cold World (about 4 pounds).

  10. Good post. I have also come to the “light” and have started carrying more “UL” packs, but not just the pack, but the entire pack. It is nice…

    I too pack everything that I do not need for the day inside the packs main compartment and the rest outside. However, I tend to split it up somewhat. For instance, I carry a lanyard with a tiny compass/thermometer, small knife, micro light, fire steel (rod) and whistle in my cargo pants pocket. This way, these essentials are always with me. I also use a Multipack (from ZPacks) attached at my chest with items I can get to quickly while still hiking such as my ditty bag (w/ all of my FAK, repair items, water purification tabs, meds, soap, etc…) a CloudKilt and a Joby Gorilla Pod (luxury item). (All of this comes to just under a lb.) My camera is usually in one of my front pants pockets (I have found this place to be the easiest/fastest place to get to my camera at). I usually put my tent stakes, TP, wind shirt, sunglasses case, water filter & reservoir bags and alky fuel in the large outside center pocket. If the pack I am using has side pockets some of these items will be shifted to the side pockets to even up the weight. However, the tent is inside the pack at the very top so it is the first thing that I can pull out at camp. The rest is packed securely away though.

    As you mention, it is very important when it comes to packing a frameless pack. For this reason I have a certain way that I pack my packs in order to obtain that near-rigid structure which makes carrying a frameless pack enjoyable for me. I have also been trying to be more aware of my Center of Gravity to though. For this reason, I try to have very little weight in the outside pockets which are farther away from my CoG. The more weight in these pockets, the more my body is being shifted away from my CoG and the more effort that I have to put into it to try and compensate for that. The Multipack on my chest also helps somewhat to correct this, however, I also try to keep it as light as can be too. I will admit though, this is definitely easier to achieve though with light weight pack weights and with less bulky items inside.

  11. One easy way of distinguishing an UL pack besides weight is what I call the “shake test”.

    You take the pack, flip it upside down and the more straps and randomness that is flying all over the place, the less UL it is. Seriously, try it. The more bells and whistles, the more of a clusterbomb the straps form when the pack is upside down.

    Of course, this is looking at UL as a philosophy of simplicity rather than the more traditional view of sub-10lbs. I really dig the simplicity of UL so I strive for simplicity with weight reduction.

  12. What is an Ultralight Backpack? It’s a backpack that is really really light. If its over one pound, its not ultralight. 32oz compared to 9-15 oz is a big difference. Let’s draw the line at 1 pound, anyone agree? After all, what’s lighter than ultralight?

  13. I like the simplicity of the ‘one compartment’ but the mesh pockets make you look like a walking garbage bag! Hope I don’t get behind one of those on the trail. Just sayin…
    Those Hyperlites look great. Can’t wait to try one. Good article.

  14. Don’t forget waterproofing aspects of a bag… some are more waterproof than others; some come with a a cover and others do not. I took a Six Moons UL pack this past weekend and thought it would be fairly water tight with all the seam seals and impregnated material…. not so much. I had six inches of water in my pack the next morning. I rolled the top and hung it from a tree, but still got a pack full of water. Good thing I had a Cuben dry bag for my clothes or I would have had to call it a day. I spent most of my morning pulling apart the bag and contents to lay out to dry.

  15. Don’t forget comfort. There is a point when something lighter compromises the actual comfort that ultralight is supposed to accomplish. Each person needs to evaluate what works for them, especially regarding no hipbelt. Back in the day when I had a 5 pound backpack I would take off all the pockets and use that as a daypack on layover days. I had camera gear and warm stuff etc to carry and carrying a comfortable pack on my hips with 15 or more pounds was way better than 10 pounds on my shoulders only.
    In later years I went from 50 lb. pack to 30 lb.for 7 days in the mountains and loved 6 Moon Designs because it was rated for 35 lbs. (I needed a very warm bag and clothes just to do this sport. Anything with less weight would put me at risk. Loved the 32 years backpacking!)

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