Symbiosis Gear: Ultralight Backpacks for People With Boobs

Maria Weidich


There are enough barriers for women in the outdoors, and Sarah Berkeley of Symbiosis Gear is on a mission to obliterate these obstacles by designing frameless, ultralight backpacks specifically “for people with boobs”.

“I just felt excluded,” Sarah said.  “Men had all these options, in terms of packs. There really wasn’t anything for women in the ultralight space.”

Growing up on a farm in Michigan, and later the mountains of Colorado, Sarah came from a household of creatives.  From learning to sew, to woodworking, gardening, running lemonade stands, and even helping build her family’s home, Sarah was always making stuff.

She went on to earn a Master of Fine Arts from the University of Michigan writing her thesis on, of all things, walking. As simple as it sounds, there’s plenty of discussion on the topic, she said. 


Sarah on the Bridge of the Gods along the PCT

As part of her research, Sarah walked roughly 20 miles from her residency headquarters north of Chicago to her home in the Windy City. “I loved the experience; from using my body as a form of transportation, the way time passed, what I was able to observe. It just felt really good compared to zipping around in a car or train.”

This experience, along with completing Vermont’s 273-mile Long Trail years later, set the stage for Sarah’s next long walk and unintended knowledge of backpacks.

After thru-hiking the Pacific Crest Trail in 2019, Sarah had weathered not one, not two, but three ill-fitting packs along her 2,650-mile long journey. From a pack that impeded arm movement, to one that sat low like a full diaper, to one that squished her breasts all the way through the state of Oregon, Sarah’s frustration grew.

“The boob squish was terrible,” she laughed.

Against these odds, Sarah successfully completed her PCT thru-hike, but she didn’t stop thinking about her disagreeable backpacks. After being shut down more than once to get a pack customized to her specifications, she exclaimed, “I’m gonna make my own then!”



First, Sarah needed to justify the need. “Was I the only one, or are there other women?” She sent out a survey and after 200 responses poured in, 94% of women surveyed expressed, “it’s about damn time” a pack designed for women entered the UL backpacking space.

“It gave me the validation to go ahead with it,” Sarah said of launching Symbiosis Gear. Like the name implies, she aspires the brand to have a symbiotic relationship with the world.  

“Trees are a wonderful example; they use a ton of resources like sun, water and nutrients, but they also give so much by providing clean air, shade and habitat. Although it takes resources to create our products, my vision is that the benefits they provide balances out the resources required.”



Working with backpack consultants, various fabric sources and manufacturers, Sarah went through prototype after prototype.

After two years of dedicated research, Sarah found herself in possession of 500 backpacks made for women like herself. “I felt really confident this is a great product and people are going to love it,” she said, recalling the moment. “But, oh my gosh, now I have 500 backpacks!”

The Aspen, named after the light and nimble tree, is a frameless, roll-top, 38L pack and is exactly what Sarah wished she had on her own PCT hike years before.  

One key difference is the pack’s S-style straps that contour around the chest and are ideal for people with round shoulders and round chests. Simply put, they’re “boob friendly”.

In addition, the sternum strap is highly adjustable, offering a 17-inch range, and offers a little elastic stretch for additional comfort. The daisy chains run down the full length of the straps making the sternum strap fully adjustable, top to bottom.

The hip belt is also widely adjustable, and even completely removable.



Curvy or not, Sarah designed the pack to be inclusive, which fits a wide range of shapes and sizes. “Prove me wrong,” she laughed.  “So far we have not gotten there, and it really does fit a wide range.”

As she gears up to thru-hike the Continental Divide Trail later this year, you better believe Sarah will be putting the Aspen through the ringer. “I’m finally doing a hike with a pack I love!”

“I think the best part is still coming,” Sarah said. “I’ve seen women try it on and get excited about it, and that’s the whole reason I do it. My vision for this business is big. I want girls to see a whole section of products just for them so they feel welcome and supported on any outdoor adventure they want. I’m on a mission to change the industry. Backpacking is hard enough, women shouldn’t have to bear physical pain in the process.”



Originally from Alaska, Maria currently resides in Montana with her husband, two young daughters and chocolate lab named Echo.  When she’s not chasing her kids or that next running goal, you can find her weekend-warrioring in the mountains or thinking about her next cup of coffee.



The Aspen - Women's Ultralight Frameless Backpack by Symbiosis Gear
The Aspen - Women's Backpack by Symbiosis Gear




Mogul    “Life is Good”

Mogul “Life is Good”

I thru-hiked the AT and the PCT. It was on the CDT when I finally heard about it. “Symbiosis Gear” ultralight backpack explicitly designed for people with boobs. And three hikers I am friends with raved about it. It is about time a female-designed backpack was made.

Mogul “Life is Good”

Mogul “Life is Good”

I thru-hiked the AT and the PCT. It was on the CDT when I finally heard about it. “Symbiosis Gear” ultralight backpack explicitly designed for people with boobs.  And both hikers raved about it. It’s about time a female-designed backpack was made. 



No load lifters? And please don’t tell me I don’t need them, I have done over 9,000 miles of long trails.

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