Symbiosis Gear Aspen Backpack Review
The Symbiosis Gear Aspen UL backpack is an ultralight, frameless backpack designed for women by a woman. This makes it unusual in the world of ultralight backpacks, where most packs are unisex. This mostly means they are made for men.
- Type: Frameless
- Voume: 48L (38L main, 10L external pockets)
- Weight: 25 oz/ 708 g
- Gender: Unisex but made for women and those with narrow shoulders, with S-shaped shoulder straps
- Pockets: 5 open
- Waist belt pockets: No
- Hydration compatible: No
- Load lifters: No
- Maximum recommended load: 20 lbs
- Sizing: One size
- Materials: 420D Extreema (Nylon), Spundra UHMWPE
- Fit: 5’2” to 6’1” height
- Hipbelt range: 18”-50”
Backpack Storage and Organization
The Aspen is a top-loading backpack with a total capacity of 48 liters. This includes 38 liters of internal volume and 10 liters in the external pockets. The pack bag has a roll top with snaps for closure and a Y-strap to hold it down.
There are five open pockets: a large front stretch pocket good for storing stuff you need easy access. There are two large side pockets made of solid, durable 420D ripstop nylon fabric. It is possible to grab a water bottle from the side pockets and put it back in. It can be done with a Nalgene, but it’s much easier with a tall bottle with a smaller diameter, such as Smartwater or a similar brand. One pocket will hold two such bottles or one bottle plus other gear. Both pockets have a cord-locked shock cord on the opening.
There is a fourth pocket on the bottom of the pack. It is the same stretch fabric as on the front pocket. It could be a good place to put a map, a sit pad, or a bandana. Also, anything inside it can get squished when you set the pack down. This pocket is most secure when the pack is full, but it’s not a good place to keep valuables.
The fifth pocket is an integrated stretch phone pocket on the right shoulder strap. I was initially skeptical about this pocket, but it holds onto my phone quite well, and it doesn’t impede shoulder movement.
You can fit a full-size bear canister vertically in the pack, then pack around it. However, this takes up a significant amount of the usable interior space. It is recommended that you add a sit pad to the back for padding. You could also put it on top using the Y strap; however, you would probably want it empty or filled with light things, rather than adding a large amount of weight high up on the pack and throwing off your balance.
There are no pockets on the waistbelt. However, a detachable pouch is in the design phase at Symbiosis Gear.
Backpack Frame
The Aspen is a frameless backpack with a padded mesh back. The pack is outfitted with female-friendly S-curve shoulder straps. I found them quite comfortable, and they should fit any breast size. The sternum strap is very easily adjusted along the shoulder strap. Part of it is stretchy so that you can get a firm yet forgiving fit.
The Apen does not use load lifters, and they’d be pointless on a frameless backpack anyway because there’s no frame to anchor them to. When packing the pack, you want to make sure you don’t oversuff it so it barrels against your back but lies flat against it.
The waist belt is simple 1.5” webbing, so it does not transfer load to the hips. The buckle lies nicely flat and is easy to operate. Wide elastic bands wrap around the belt that you can use to manage any excess belt webbing
External Attachment and Compression
The Aspen has zigzag side compression straps that run the length of the pack and can also be used to attach items to the sides. There is not much excess length, so it’s difficult to attach anything bulky. There is a long Y-strap that can be used to compress the top of the pack or to secure a bulky item, such as a foam sledding pad.
In addition to shock cord over the front stretch pocket, there are gear loops at the base of the pack to facilitate carrying trekking poles. There are also daisy chains on the shoulder straps for attaching accessory pockets.
Maximum Recommended Load
The Aspen is rated for 20 lbs, and when I go over that, it becomes uncomfortable. Ideally, you’d want to get your base weight (minus food, fuel, and water) down to around 10 lbs and carry a minimal load to fit into the pack’s 38L of closed capacity and 10L of open pocket space. That’s a pretty minimal summer load by my standards, with few nice-to-have comfort items. While the Aspen is a backpack designed for women, you’ll want to shrink your load volume and weight substantially to use it comfortably, particularly if you use a backpack with a frame and hipbelt today.
Recommendation
The Symbiosis Aspen is an ultralight frameless backpack designed for women. With a total capacity of 48 liters (38L of closed storage), it’s primarily designed for thru-hikers who want a durable ultralight backpack made with thick nylon (Extreema) rather than more expensive Dyneema or Ultra fabric. That said, the Aspen would also make a nice pack for shorter-duration or weekend backpacking trips, provided you can keep your total pack weight under 20 pounds.
Disclosure: Symbiosis donated a backpack for review.
About the Author
SectionHiker never accepts payment for gear reviews or editorial coverage. When you buy through affiliate links on our site, we may earn a small commission at no extra cost to you. Help us continue to test and write unsponsored and independent gear reviews, hiking and backpacking FAQs, and free hiking guides.
My partner got this pack at the end of summer. She’s 5’7″ with ~17″ torso, 140#, 34D. Here’s what she has to say:
Awesome features (all the good stuff): The fit, of course. Truly no boob smoosh! The 400 denier fabric is economical, fairly light and really, really durable (but not as light as a 210 denier fabric or as waterproof as Dyneema or Ultra). I mean it’s seriously robust and should last a gazillion miles. The large side pockets with draw cords. The bottom pocket. The side compression straps to shrink the pack volume when I have a smaller load, or keep me together when I stow my trekking poles or carry an umbrella. The top Y strap. The stretchy and snug sternum strap. The shoulder straps that are comfortable for my narrow shoulders and neck. Daisy chains on the shoulder straps for my InReach. The back panel which has a bit of padding and a breathable fabric — it seems to keep my back drier than other frameless packs I’ve carried (think similar to ULA). No hip belt pockets to get in the way of my fanny pack. Seams are all beautifully taped and sewn. The roll top has stiffeners which makes packing up a little easier. And (again) the awesome shoulder straps that don’t smoosh me.
About the fabric: ULA also builds packs with a 400 denier fabric (not Extreema), which is much more robust and durable than the nylon fabrics most other pack makers use. But durability comes with a weight penalty compared to the 210 denier fabric used by pack makers like Pa’lante, Atom Packs, SWD, and MLD. Gossamer Gear even uses a combo of 70 and 100 denier fabrics which saves a lot of weight at the expense of some longevity. Water beads up on the dwr-treated Exreema but it’s nylon and eventually it soaks through so I use a pack liner.
Design thoughts (none of these things are deal-breakers for me): My phone occasionally falls out of the shoulder strap pocket when I’m leaning over to pick up something I dropped. Using 210 denier Ultragrid fabric could save at least a couple of ounces (and be plenty durable). I’d like the hip belt to be fully removable because I’m not ready to cut it off completely. I’d like a cute color, but I know adding SKU’s makes production and inventory more expensive and difficult. The shock cord cris-crossing the front pocket is too short and makes stuffing the pocket difficult (and overstuffing it is impossible). I just removed it, but it would be easy to put a longer piece in its place. My BV450 doesn’t fit comfortably.
Weight: At 25 ounces this is a little heavy IMO. Using a 210d fabric would save 2 or 3 ounces. The padded back panel probably adds about 1.5 ounces. Stripping the shock cord on the front pocket saves around 0.5 ounces. I could cut off the waist belt and probably save 1 or 2 ounces. And it’s minor, but there’s no need for two sets of daisy chains on the shoulder strap. So if I compare to Bunny’s MLD at 18 ounces it seems comparable, kind of — but it’s 25 ounces so the “extra” weight is there, for sure.
Value: The price seems a little high, especially if you don’t factor in the design or the quality sewing. Nylon is inexpensive compared to Ultra and DCF, and most frameless packs made from Robic or Ultragrid (pretty similar to Extreema) are 20-30% less expensive than the Aspen — but none of them have the Aspen’s design features and friendly fit. And I love the fit!
Anything else? I love that Symbiosis Gear is woman-owned. I can accept that the packs are made in Vietnam but I’d prefer MUSA, especially at this price point (yes I know Palante, SMD, Gossamer Gear and other packs including Osprey and Patagonia are also made in Vietnam). Most of all I’m excited about my pack and can’t wait to put a lot more miles on it!
There’s nothing terribly female specific about this pack other than its made by a company owned by a female. Other backpack manufacturers almost universally switched to using S-shaped shoulders straps a few years now. ULA did it over 10 years ago. I think its great that more women are designing packs though and look forward to seeing how Symbiosis can differentiate itself going forward. For example, special pockets for holding female specific gear, vest-style straps that don’t smash boobs flat, better sizing for women, and so forth.
In that case, list price on this bag is absurd. Get a ULA CDT in Robic for $220 and be done. Pocket the $80 difference. The reviewer should have called this out, not make it a Recommended product. (My mate didn’t pay list, and she will argue in favor of the superior fit. Not my pack so I don’t have a vote)
Philip, since you deleted my follow up comment I request that you delete my initial comment. My comments about price and the lack of justification for a Recommended product label are valid given your follow up to my post. We can agree to disagree, but I choose not to contribute content to your site from now forward. Peace.
I didn’t delete your comment. It just got flagged by my spam filter. About 75% of all comments are held in moderation by it for me to manually approve. I’m fine with that since I don’t want my website overrun by sopam.
Philip, it’s your site so I have no issues with you moderating as you see fit. I do have an issue, however, with your comment to my post without allowing rebuttal. Again I ask you to delete my initial post since your comment likely would be considered by most readers as contradicting mine. Most charitably, your comment suggests there is nothing special about the Aspen pack in spite of your reviewer labeling it a Recommended product. Since that’s the case, why delete my comment that the ULA CDT is a very comparable substitute at a fraction of the price ($220 vs $300, a 27% discount)? That shouldn’t be considered challenging in any way since her recommendation stands on its own, right? Oh wait, equivalent packs but not equivalent prices. Or did I miss something?
It wasn’t meant to be a contradiction, just an observation, which Wanda didn’t make because she hasn’t reviewed 300+ backpacks and I told her to just do a standalone review. Rebut away. I welcome cogent discussion and you’re a valued commenter/contributor. The last thng I want to do is to censor your thoughts. Since this was published, I’ve glanced at a few reviews of this pack on other sites, like Gear Junkie, and my comment was actually in reaction to their gushing praise of this pack because it is designed for women. Its a nice pack according to Wanda, but I’m just not that wowed even though I’ve been advocating for female features and sizing on packs for over a decade. I was hoping to see something earth-shatteringly new.