Mystery Ranch Women’s Radix 31 Backpack Review

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A backpacking trip is only as good as your backpack. There is nothing worse than having an ill-fitting backpack to lug around your temporary home. Well since 2000, Mystery Ranch has been refining and improving to minimize the burden on your back. They didn’t miss a beat with their Mystery Ranch Women’s Radix 31 backpack. I had been looking for a lightweight option for my shorter trips because my 55 liter pack always had extra space.

Mystery Ranch has quite a selection and I chose the women’s model of the Radix 31 due to the narrower fit of the shoulder harness and the women specific fit. I used the sizing chart on Mystery Ranch’s website and the M/L was recommended. The fit is perfect and has many adjustments. It looks like since I have ordered, they have changed their sizing options to an expanded 4 sizes: S, M, L, XL.

Easily access the side pockets from the front
Adjustable height of the harness


I took some time to get to know the Radix 31 before taking it out for some test runs. Starting with the shoulder harness, I love that the torso length is customizable with an easy-to-adjust hook and loop panel. I am 6 ft. tall and slim, so torso length can be an issue for me in a smaller pack. I was able to adjust the harness to the perfect height with this simple adjustment.

The waist belt is beautifully padded but super light. It was plenty long enough to fit nicely around my hips. Mystery ranch used 1 inch webbing for the waist belt which really cut down on the bulk in the front. The buckle is neatly shaped so that is does not poke into the belly when the belt is tightened. The waist belt has a large pocket on both the left and right side. This may sound like a lot of bells and whistles (weight) but the pack is surprisingly light and weighs in at 3 lbs.

The Radix 31 was really designed with the wearer in mind. In addition to the great fit features I mentioned, Mystery Ranch made the side pockets easily accessible while wearing the pack. The pocket openings angle toward the front at a comfortable angle to reach back and dig around in the pocket.  The openings of the side pockets have an adjustable bungee so no matter what size your water bottle is, you will be able to get it in and out easily.

The full length zipper opens up the pack to easily access your gear


Mystery Ranch designed this pack to be lightweight and comfortable for the user. Part of that comfort is the simple, easy design of the storage compartments. The storage pocket on the back of the pack is plenty large enough to tuck away your puffy and deep enough for a small sitting pad or trekking poles. The opening is secured with a adjustable bungee to keep things where they belong.

The top opening is also closed with an adjustable bungee drawstring. Mystery Ranch thought ahead by adding a full length zipper to the pack. It is a lightweight YKK zipper that appears water tight (I haven’t had to test that out yet). They impressed me further by installing a buckle that covers the top of the access zipper. This allows you to lay the pack down and unzip the full length of the zipper without your gear spilling out the top opening.

Inside of the pack, there is a sleeve pocket that will fit my hydration bladder. It looks like it will fit the normal sized 2 liter bladder with no trouble. Above the hydration storage, there is a hole on either shoulder to run the bladder’s tube through to the front.

The excess strap wraps up nicely


Have you ever broken an essential strap? Or wanted to remove a strap? Mystery Ranch thought ahead on this one. The cinch straps are easily removable without any trouble. Genius! There is both an upper and lower cinch strap and an adjustable strap/buckle combo to secure the top flap of the pack. All of the attachment points are removable in case you need to repair or replace a strap. No need to have a new one sewn.

At the end of each of the cinch straps is a loop that allows you to insert the hook and loop pieces that are included with the back pack. You simply roll the excess strap webbing around the piece of hook and loop. This keeps the excess strap tucked neatly away and you don’t look like a jellyfish with all the excess webbing swaying in the wind.

I would prefer that the chest strap adjustment slide from top to bottom. It was not an easy adjustment.


The empty weight of the Radix 31 is 3 lbs. You can choose to remove the aluminum frame and/or the rigid plastic panel in the back of the harness to customize the feel or shed some excess weight. I found that the fully loaded pack was super comfortable in both configurations. I plan to leave out the extra pieces unless I am doing something really long. The versatility of this design makes this an all around great day pack and backpack for shorter trips.

I tested this pack on a short overnight trip in Michigan. I was easily able to store everything I needed for 1 night including the tent, cookware, stove and sleeping bag. My food, puffy and water bottle were stored on the outside pockets and really balance the load. Even loaded, the pack was super comfortable without the suspension frame. 10 out of 10!


  • Weight: 3.1 lb.
  • Volume: 1755 cu-ins
  • Dimensions: 23″x12″x9.5″
  • Harnessing Style: Frame
  • Materials:  Technical Ultra-PE Birdseye, Recycled 100D Robic Ripstop
  • Available Colors:  White/Hunter and Black/Hunter
  • Available women’s sizes:  S, M, L, XL


Mystery Ranch designed the women’s Radix 31 Backpack to be lightweight and easily customizable to fit a women’s shape. The pack is made of the durable, ripstop materials that you would expect in a backpack. Despite the durable feel of this back pack, Mystery Ranch did a great job of keeping this pack super light. The comfort and feel of the Radix 31 is direct evidence of the quality that Mystery Ranch delivers. This product certainly did not disappoint!

I had a nice overnighter with the Radix 31 without any complaints about my pack. It will surely become a staple piece of gear as I travel towards the Rockies for the next 6 months. I plan to use it as a day pack on long mountain hikes and for short 1 or 2 overnight trips. Once I was home from the overnight, I tried out the pack with the waist belt removed. It was incredible! It is like two backpacks in one that makes this pack amazingly versatile.

I thought that the pack was exceptionally priced at $219 dollars. It is a high quality pack and I was very pleased at the value for the price. If you would like more information or are interested in the Mystery Ranch Radix 31 for yourself, check it out at

Sara Fillman: Sara is an avid ultra-marathoner and outdoor adventurer. Living in Michigan, Sara has ample opportunities for outdoor sports during all seasons. When not open water kayaking on the Great Lakes or backpacking in some distance mountains, she can be found ice climbing in Norther Michigan at the Pictured Rocks National Lakeshore. She is constantly looking for the next big adventure.
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