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Mystery Ranch Urban Assault 21

rated 4.5 of 5 stars
photo: Mystery Ranch Urban Assault 21 daypack (under 35l)

A relatively small, highly durable daypack that moves easily from commuting to the trail. While this is no lightweight for a backpack this small, it is comfortable to carry and supremely easy to access the contents. With inner sleeves that swallow a laptop, tablet, and cables, it would be a super solution for commuters who prefer a backpack to a briefcase. It's basically a smaller, stripped-down version of one of my favorite larger daypacks, the 38 liter Mystery Ranch Snapdragon. The lack of any dedicated hydration options is my only quibble, but carrying a plain old water bottle isn't bad.


  • Access to interior
  • Organization options
  • Simple, durable design
  • Carries extremely well


  • Costly if not on sale
  • Heavier than some alternatives
  • No hydration options



As I transitioned from 'mothership' for our kids on day hikes to only carrying my own stuff, I struggled with the question of what kind of really small day pack would work best for me. I often see rocky trails and branches that can scrape up a lightweight backpack, and I much prefer a backpack that is going to last for ten years than a lighter-duty option that probably won't last for half that time. Also, these packs are so small that having a usable hip belt doesn't make much sense. I narrowed the field to this and Osprey's popular Talon 22, and I landed on the Urban Assault thanks to a 30% off sale price.  I'm very happy with that decision.


The Urban Assault is a 21 liter day pack; mine weighs 2.1 pounds on a digital hand scale. That is meaningfully more than many available lighter-weight options, which range from minimalists under a pound to swiss army packs with many features and options that are 1.75. pounds or less.  

The pocket situation is simple—one zippered pocket in the top, two smaller zippered pockets in the interior on the left and right sides, and two sleeves that sit where you would expect a hydration reservoir to be. And, of course, the rest of the pack's main storage section.

20181118_101653.jpgThis shows the pack unzipped and one of the interior pockets unzipped tool.  
20181119_094000.jpgThe top pocket is decent sized for a small pack. You can also see the grab loop above, and the buckles are for the top adjustment to the shoulder strap.  

20181118_101618.jpgA pulled back view of the suspension and the mesh-covered back pad.  

What that extra weight gives you is a solid, durable solution. The shoulder straps and back are well-padded with firm foam covered by hefty mesh, the zippers are robust and effectively blow-out proof, and the bag is made from 500d cordura. It's a thicker, more durable fabric than most lighter-weight backpacks, yet a compromise in that it's not the ultra-tough (and relatively weighty) 1680 denier ballistic nylon on one of my large daypacks.  


This is a decent representation of how unzipping gives you access to the inside. For purposes of scale, that's a one-liter hydro flask bottle, a mid-weight fleece, and a light wool sweater in there.  

The main visual and unique part of this daypack is undoubtedly the three-zipper access to the content. Like a panel loader, unzipping this backpack lets you get at anything inside easily. The zippers are waterproofed and overbuilt - not quite as heavy-duty as the zips on a larger pack I own, Mystery Ranch's now-discontinued Snapdragon, but more than heavy enough for a lifetime of use.

On a much cooler day, I got ready for a walk and brought a bottle in a foam carrier, an extra fleece, and a puffy jacket.

As the photos show, the outside of the backpack looks is simple—no exterior pockets, zippered or otherwise.  


No hip belt, so this is about carrying weight on your shoulders. For a pack this size, that's not a serious issue. I haven't yet found a pack this size that can both sit on my shoulders and have a hip belt actually sit on my hips anyway. But Mystery Ranch does take comfort seriously. The foam it uses on the back pad is sturdy, and the shoulder straps have two thicknesses of foam—thicker at the top side of the shoulder straps where you bear weight. The pack also has a small removable plastic frame sheet that protects your back from odd-shaped items you might shove in.

The photo above shows one of the side zippered mesh pockets on the inside—about big enough for a knife, keys, and a few energy bars. The two grey nylon pieces in the middle are the sleeves for a laptop, or a wool hat or water bottle, perhaps even a light wind shell. It happens I was carrying a Patagonia fleece in there. No compression straps, but with the plastic frame sheet and thicker fabric for the pack bag, compression straps don't seem necessary.  
20181119_093938.jpgSide view of the shoulder straps and back pad

The sternum strap is interesting primarily due to an unusual mechanism for sliding it up and down the shoulder straps. Unhitch the elastic, and the slider moves. Unique adjustment.  




Long loops of cord intertwining the zipper pulls are a Mystery Ranch staple and make this easy to open and close, even if you're wearing gloves.

The top lid hides a key clip tethered to the bag. 

20181119_093947.jpgbetter shot of the zipper pull

While it may not be super easy to see, this is a shot of the interior sleeves with a MacBook in one sleeve and a tablet and power cord in the other. The sleeves are sizable and could probably hold a heavier 15-inch PC if needed.  

The interior sleeves that appear built more for a laptop and tablet could grab a mid-sized hydration bladder, but this pack has no opening for a hydration hose. I suppose you could cut a small hole; Better off just tossing a water bottle in.

If you like attaching things to the outside of backpacks, this has three relatively light-duty nylon loops—two on the top, one in the middle on the front—and a heavy duty strip of webbing stitched to the bottom. 



This pack has accompanied me on many day hikes ranging from flat canal towpaths to steep, rocky trails over the past few months. It also accompanied me on a few metro rides into town, armed more for work than the trails.

Though I generally don't carry more than 10-15 pounds in it, I overloaded it to 20 to see how it would feel. I'm happy to say this can carry as much as you can stuff into it without putting any serious dent in your shoulders. That is not an accident—many larger backpacks I have used with less well-padded or designed shoulder pads leave my shoulders feeling tired. I haven't intentionally dragged it over rocks, but the normal use it has seen hasn't left any noticeable wear.  

Most of the hikes have been in cooler weather, so I haven't really tested how this handles a sweaty hike in a t-shirt. Wearing a thicker layer that better disperses sweat, the back pad has barely felt damp at the end of any hike.  

The shoulder straps are pretty long—so even a very large person or someone layering for winter could readily use this as a smaller daypack or summit bag. This pack has no compression straps, for for something this size and pack fabric this thick, I can't see how compression straps would accomplish anything.  


This isn't what you want if you are looking for very lightweight, a wide variety of storage options, a hip belt, or a good hydration bladder solution. If you want something small that will give you a comfortable carry, survive years of rough handling, with enough storage options to make your life easier, think about this. If you value the ability to open a pack up and see the contents rather than fishing into it from the top, you will really like this.

Finally, Mystery Ranch is a great company that designs backpacks well and stands behind them. I'm very happy with this. (Finding it for 30% off was very helpful, because the $139 retail price tag is a little high in my opinion.) 


A couple of months of hiking with this small daypack.

Over ten years of experience with two larger Mystery Ranch backpacks—the expedition-sized G6000 and the 39 liter Snapdragon, which has the same tri-zip design as the Urban Assault.

I tried one similarly-sized smaller backpack, an Osprey pack intended for cycling that I received as a gift. The top edges of the shoulder straps partially pulled out; after a warrantee repair, the pack ended up with our son as a small daypack he uses to go to the gym and for outings during a trip to Europe.

Source: bought it new
Price Paid: $97

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Price Current Retail: $69.50-$125.00
Historic Range: $55.16-$139.00
Reviewers Paid: $97.00
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