Review: Black Diamond Trail Blitz 12 and REI Flash 18 Daypacks

Ultralight Daypacks
Black Diamond Trail Blitz 12
$50, 12L/732 c.i., 6.5 oz.
One size

REI Flash 18
$40, 18L/1,100 c.i., 9 oz.
One size

When considering whether to carry a light daypack or summit pack for side hikes or peakbagging on a backpacking trip, I’d normally weigh the length of the side hikes—i.e., how far I’d have to carry my backpack as an oversized daypack—versus the weight the daypack adds to my backpack. But with these two frameless, ultralight packs, each weighing no more than about three fingers of water in a liter bottle and packing away as small as an ultralight rain shell, that’s an easy decision: I take one of them.

I carried the Black Diamond Trail Blitz 12 with about eight pounds of layers, snacks, and water inside on a 13-mile dayhike from a campsite above Bechler Canyon to the Shoshone geyser basin during a five-day, 56-mile backpacking trip in Yellowstone National Park.

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Black Diamond Trail Blitz 12 daypack.
Black Diamond Trail Blitz 12 daypack.

A top-loading pack without a lid, the Trail Blitz 12 has a simple, adjustable strap with a hook that attaches to a fabric loop on the front to quickly access and seal up the main compartment. With no frame, padding, or even a waist belt, the pack can carry essentially as much weight as you’re willing to bear on your shoulders and back—which for most people will be 10 pounds or less. The shoulder and sternum straps keep it fairly stable on your torso when hiking and scrambling (but it’s definitely not made for running—the Black Diamond Distance 15 is much better suited to that).

At 12 liters/732 cubic inches, it has the capacity for a few extra layers and some food and a water bottle or two—what you’d carry on a side hike or an ultralight dayhike or scramble. I found it perfectly comfortable with about eight pounds inside, including water, food, layers, and a DSLR camera, on a roughly six-hour, 13-mile dayhike while backpacking in Yellowstone. One zippered internal pocket holds small valuables like keys, sunglasses, etc.

Side sleeves on the Trail Blitz each hold one compact trekking pole like the various models of Black Diamond Distance Z poles. But poles that aren’t as compact when collapsed or folded will stick out too far above these side sleeves, potentially falling out easily. Four small loops on the back panel allow for attacking it to larger packs—but the Trail Blitz also simply rolls up so small that it’s easier to just jam it inside a backpack’s main compartment or an external pocket.

It turns inside-out to store in its internal pocket—which is remarkably easy to do, and reduces its bulk as well as getting its pack straps out of the way when storing it inside a larger pack. The very light N210-denier mini-ripstop pack fabric still looks new after hard abuse and will last for years—in fact, with essentially no vulnerable parts except one zipper that’s internal and not used frequently, it’s hard to imagine this pack not lasting longer than most of your gear.

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The REI Flash 18 ultralight daypack.
The REI Flash 18 ultralight daypack.

I carried the REI Flash 18 on an 18-mile, out-and-back dayhike on the Beamer Trail during a six-day, 74-mile backpacking trip in the Grand Canyon. A friend carried it on the previously mentioned 13-mile dayhike while backpacking in Yellowstone, and found it adequately comfortable with about five pounds of layers, snacks, and water inside.

With more space at 18 liters/1,100 cubic inches (and weighing a few ounces more) than the Trail Blitz 12, the top-loading Flash 18 can fit everything one person would need on an all-day hike even in cold weather, or probably fit everything that two people would need on a side hike during a backpacking trip—limited only by how much weight, especially in food and water, that the person carrying it is willing to haul with a minimalist daypack.

The REI Flash 18 ultralight daypack.
The REI Flash 18 ultralight daypack.

That said, the Flash 18 design, while still minimalist, also offers slightly more comfort than the ultra-minimalist Trail Blitz, with a thin, flexible, removable foam back pad, stretch-mesh shoulder straps that are more shaped and wider than those on the Trail Blitz, and a removable webbing waist belt (the sternum strap is also removable).

While it lacks the Trail Blitz’s side sleeves, the Flash 18 has a zippered front pocket with space for small items like map, gloves, hat, headlamp, and map—although that pocket has no bellows to it, reducing its space when the main compartment is stuffed to capacity. Without a lid, the Flash 18 has a drawcord top closure with a small nylon flap to keep light precipitation out of the interior. A daisy chain strip on the front facilitates lowering the pack (off a short cliff when scrambling, for instance) or attaching items to the outside, and there’s an ice axe loop, though you’ll need to add at least one strap for those purposes.

Turn it inside-out—easily done, even with the back pad inside—and it converts to a stuff sack large enough for a three-season sleeping bag. There’s an internal bladder sleeve and a port, both lacking in the Trail Blitz.

Given its larger capacity and nominally more “featured” design, the Flash 18 also occupies about twice the space inside a backpack as the smaller Trail Blitz 12—its weight and bulk compare to an ultralight rain shell. The ripstop nylon fabric is tough, and with one lightly used zipper, you can also expect the Flash 18 to endure many years of hard use.

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The REI Flash 18 ultralight daypack.
The REI Flash 18 ultralight daypack.

Both packs come in one size that fits my 18-inch torso fine; given that they’re intended for light loads, and have no suspension or padding, they’ll “fit” torsos roughly 16 to 20 inches, or all but very short or very tall hikers.

By the way, both of these packs fit a 15-inch laptop and function well as a convenient, packable, light carry-on for flying—albeit lacking the features, like external pockets and other organization, of many carry-ons.

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The Verdict

There’s nothing fancy about these ultralight daypacks—and that’s precisely their appeal. The Black Diamond Trail Blitz 12 and REI Flash 18 are simply two no-frills, minimalist, inexpensive, ultralight daypacks that can carry several pounds and are light and packable enough to take anywhere, from backpacking trips where you plan to take side hikes to bike commuting and as a flight carry-on.

They differ only in capacity and slightly in features. For just an extra 2.5 ounces and noticeably more bulk, the Flash 18 offers measurably more capacity and a bit more comfort than the Trail Blitz 12—a reasonable tradeoff, unless you simply want the lightest and most compact ultralight daypack.

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See “The 10 Best Hiking Daypacks,” which includes my expert buying tips, and all of my reviews of hiking gear.

See also my “8 Pro Tips for Preventing Blisters When Hiking.”

NOTE: I tested gear for Backpacker Magazine for 20 years. At The Big Outside, I review only what I consider the best outdoor gear and apparel. See my Gear Reviews page at The Big Outside for categorized menus of all of my reviews and my expert buying tips.

—Michael Lanza


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5 thoughts on “Review: Black Diamond Trail Blitz 12 and REI Flash 18 Daypacks”

  1. I have the Flash 18. It handles a 2L hydration bladder with no problem (it has a dedicated sleeve for that purpose). How would the Blitz do with a bladder? Thanks!