Mystery Ranch 1 Day Assault, Fixed Harness JDM

Tantalizingly close to a perfect office EDC backpack for me, but it doesn’t fit my back very well.

Continuing with my Mystery Ranch backpack obsession this past year, I have been longing to try out their Japanese-Market-Only 1 Day Assault line up. There’s two variants of this bag, both silly expensive, I got the “fixed harness” version which isn’t what is is really called, but commonly referred to.

The reason I got this is simply because I wanted to try this bag out badly, found it at any easy place to buy from, and one thing led to another — I had to know. This is a really neat bag, but it doesn’t work for me.

What Is This

Ok, if you search ‘1 Day Assault Mystery Ranch’ and you are in the USA, then you are going to get directed to the ASAP I reviewed already. This is not the same as what Mystery Ranch sells in Japan. The 1 Day Assault is a mix and match of features and design elements from the Urban Assault 18/21, ASAP, and Front. There’s two versions, and they roughly differ like this:

  • Fixed (what we are talking about here): the harness is the same as the Urban Assault and so is the laptop sleeve. It looks like a Front on the outside though. But it’s smaller than the 21 or Front, but bigger than the 18.
  • Adjustable: this is the Front harness (from what I can tell), a mesh pocket inside, and looks like the Front. This is as close to a Front as you can get.

Left to right: ASAP, 1 Day Assault Fixed, Urban Assault 21.

Both of these bags are made in the USA, which is important I guess for the Japanese market (that’s not a joke). So this is basically a Front without the adjustable harness, but with a laptop sleeve — missing a couple other things but that’s pretty close. By way of comparison, here’s how the measurements I took of the bags I had on hand came out:

  • Urban Assault 21: 6in x 11.5in x 19.5in
  • 1 Day Assault: 4.5in x 11.5in x 19.5in
  • ASAP: 4.5in x 11.5in x 19.5in

Mystery Ranch pegs those three bags at:

  • Urban Assault 21: 25cm x 51cm x 22cm
  • 1 Day Assault: 27cm x 51cm x 18cm
  • ASAP: 30cm x 53cm x 20cm

Anecdotally the Urban Assault 21 is much bigger without looking like it, and that’s all in the depth of the bag. The ASAP and 1 Day measure identical, but the 1 Day feels smaller.

The bottom kind of has a PALS webbing row, but it’s more a handle. I don’t know what they were smoking with this, it’s odd.

Where/How to Buy

It came with that cord, but also metal pull tabs. Since metal pull tabs are awful, I’ve removed them.

Ok, you can find the product page here, this Hong Kong site sometimes sells them and ships to the US, but Sierra recently had US stock of them for unknown reasons and that’s where I got mine.

Comfort and Carry

This bag is just not that comfortable to carry. It feels the exact same as the Urban Assault does/did to me: there’s nothing major about it that is bad, but there’s nothing super comfortable about it for me either.

The main issue is my torso is a touch (maybe 1-2”) too long for both the body of the bag to sit properly against my back, and also for the shoulder straps to sit where they’ve been designed across my shoulders/chest.

It’s still a good harness, but it’s one of those things that if you are too tall, it’s going to not work well for you. Something that a few others have confirmed with me about this model. I’d say you want to be 5’-10” or shorter — or generally have a shorter torso if you want this bag.

Oh how I wish this fit me correctly.

Everything else is standard Mystery Ranch, and solid. But the bag doesn’t fit me well. One thing that exacerbates the issue on my body is that there tends to be a collection of bulk when I take it to the office at the very bottom of the bag. This causes the bottom edge of the bag to push out a bit and if the bag fit my perfectly it wouldn’t be an issue as it would fit right into the small of my back and feel fine. But because it doesn’t fit me well, this often means I choose between the straps being in an awkward spot to get that correct feel on my back, or the back riding up higher for proper strap positioning — which is what I choose. But that means that the bottom edge digs just above the small of my back and feels not great.


Packed up for the office.

I’ll ignore the fit issue and talk instead about using the bag. I put it through it’s paces taking it to the office and here’s some thoughts I developed on it:

  • The laptop compartment is great. It holds stuff really well, if a little narrow for my iPad Pro 12.9” with Magic Keyboard attached. But it holds two of them well enough.
  • The top pocket is the style that is a full clamshell opening, which is the best type Mystery Ranch does. It’s fantastic.
  • It has a morale patch field at the top, also excellent.
  • There’s another pouch at the front of the laptop sleeve which might be for a tablet, but is best used with an organizer since the bag lacks any other internal pockets.
  • Unlike the Front, or Urban Assault, there’s no top mesh pockets and that’s a huge miss. This is for sure a Bring-Your-Own-Organization type of bag.
  • The strap for the laptop area can close back on itself to make a hanger for a water bladder, but there’s no bladder hose pass through. So you’d have to leave one side of the bag unzipped, not a fan of that.
  • The bag feels really shallow, and because of that it feels very small to pack in. Like 18L at best if you are planning on needing a certain size bag. I could for sure fit all my stuff for the office in it, but the bag was often pretty full at that point.

Dear Mystery Ranch, only do the top pockets like this. Thanks, Ben.

Generally speaking: this is a good smaller EDC/Office backpack, but lacks a lot of organization you would want from that type of bag. This makes it good for those who carry bulky things, or like to use organizers that pull out of bags — but if you like having pockets for your gear, look elsewhere.


The looks of this bag are perfect. Visually the size is perfect. The morale patch field, side MOLLE, front Daisy Chain, no side water bottle pockets, and the pop of orange in the logo. If I were designing a Mystery Ranch bag, it probably would look close to this. Aces.

I also got no weird looks or comments on the bag. It was completely stealth — the proportions are great on it.


This bag doesn’t work for me, and I am going to sell it off. But I wish it did fit me correctly because it would be my office bag if it did. Ultimately, what I want is an Urban Assault 21 that has an adjustable harness. The adjustable 1 Day Assault doesn’t have a laptop sleeve — but I’ll buy it next time I am in Japan — in side by side testing with the Urban Assault I have (older model) they feel the same on my back, but I think the 1 Day is a little better/nicer feeling.

This is a really good buy from Sierra at $199 if you have a shorter torso. But if you are taller like me, it will frustrate you that it is so close to greatness, but feels too short to tolerate.

I love everything about this backpack, I just can’t stand wearing it. Bummer.

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