REI Co-op Flash 18 review

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Most multipitch climbing packs will set you back a lot of money. If you want to spend some serious dough, you can even find some high-end summit packs to fulfill your hyper-light fantasies.

Luckily, there’s a climbing pack to save the day on the other end of the price spectrum.

Enter the REI Co-op Flash 18, a longtime staple of the multipitch world. The pack was originally designed as a hiking daypack, but climbers quickly caught on and started using the Flash on longer climbs.

It’s oftentimes half the price of other climbing packs, and in many cases it’s all you need. I’ve been using one of these packs for a couple years. Here are my thoughts on the pros and cons.

Note: The Flash has been updated since my generation. The features and style are largely the same, with a couple of minor (mostly aesthetic) differences that I highlight throughout this review. Also, if you’d like to compare this pack to other top options and see our review of the latest-generation Flash, check out our guide to the best climbing packs.

REI Flash 18 review


In keeping with both its price-point and style, the Flash stays pretty basic on the features. Still, it has all the essentials.

You get 18 liters of capacity in the form of a simple top-loading sack. Inside, there’s a sleeve for a hydration bladder, a thin pocket holding a removable foam layer, and a small zip pocket at the top for keys and essentials. (On the latest Flash, the zip pocket has been moved to the exterior of the pack for quicker access.)

The closure system is a simple drawcord, with a rigid flap guiding the cords and hiding a small hydration port. There are two sparsely padded backpack straps, complete with a small sternum strap and waist belt. The waist belt is removable, should you desire to go truly minimalist.

On the front are two daisy chains, one of which has a small ice axe loop at the bottom. On the latest gen pack, these have been condensed into a single, beefier daisy. The haul loop has also been raised and simplified on the new Flash, which is a definite improvement.

And that’s pretty much it. The Flash is essentially a padded, kitted-out stuff sack with a couple extra pockets. As it turns out, that’s all you really need.

REI Flash 18


For me, 18 liters is an excellent volume for climbing. On small multipitch outings, it’s possible to throw everything on your harness, but for anything longer than a few pitches, I like to have a little cargo.

I hate getting dehydrated, and I hate getting hungry, so I like to pack a lot of snacks and water. If you’re out in the mountains, you usually want a layer or two, plus essentials like sunscreen, tape, or a camera. If you’re on a multipitch climb, odds are good you’ll have approach shoes to carry as well. The Flash is the ideal size for a small kit like that.

If it’s a shorter outing and you pack carefully, two climbers can share a single pack (whoever follows gets to carry it).

That said, you’re not going to be able to fit a whole lot of gear inside. The Flash works best carrying water, light day supplies, and not much more. For most of the climbs that I’ve encountered, that’s not an issue — as long as you’re judicious with your packing, 18 liters is versatile enough for most adventures.

The minimalist interior of the Flash
The minimalist interior of the Flash


I find the Flash to be surprisingly comfortable as long as you don’t overload it. With 3 liters of water (like I said, I hate getting thirsty) and day-climb essentials, I find the Flash to be a comfortable carry. The straps are pretty minimal, but they distribute the weight just enough that you don’t really think about it.

As soon as you start to weigh the pack down, that comfort goes away.

I once did a full-day outing with the Flash that included a 70m rope (draped over the top), a light trad rack, enough layers for cold weather, and a full day of food and water. I was able to get everything either in the pack or on the daisies, but by the end of the day my shoulders and back were hurting. The Flash is best when the gear, like the pack, remains light.

The Flash 18's removable foam pad
The thin removable foam provides a little padding for the back


This is where the Flash really earns its keep.

It’s not easy to make a pack that carries well while you’re climbing. Too wide, and the profile will get in the way of your arms. Too narrow, and you push the load out away from the body, which makes for a disorienting climb. Make the straps too big, and your shoulders will be restricted.

The Flash strikes the ideal balance of cargo and carry. The profile is narrow enough that you hardly notice it when climbing, but it stays close enough to your back that your balance isn’t affected much.

The straps are big enough to distribute the load, but minimal enough that they’re out of your way when you’re reaching to the next hold. The sternum strap is actually surprisingly useful, adding stability and keeping the shoulder straps in place.

The waist belt adds even more, but it can get in the way of a harness, so I often find myself climbing without it and rarely miss it.

The Flash 18's suspension system
The suspension system on the Flash


This (along with extra features like rope straps) is where the competitors spent their extra money. The Mountain Hardwear Hueco is made out of 400D nylon, while the Black Diamond Bullet is even burlier at 420D.

The Flash makes do with a much flimsier 140D fabric. The difference is noticeable — the material on the Flash feels thinner and slightly less tear-proof.

For what it’s worth, I’ve been climbing with my Flash for more than two years in some fairly harsh environments, and it has yet to get even a single hole in it. I don’t tend to trash my gear, but I’ve certainly put the pack through the ringer, including dangling it below me through some grovelly granite chimneys.

As long as you’re not using it as a haul bag, the Flash will generally do just fine. Plus, the thin fabric is part of what keeps the pack so light — a full 8 ounces lighter than packs like the Bug or Bullet.

As a disclaimer, a friend of mine did have his Flash develop a (fairly large) hole, but it was because a bear broke into his car and tore it apart. These packs are not bear-proof.


This is the other area where the Flash excels. Everything on the pack is simple and functional. The closure system is simple and easy, the pockets are all well-designed and well-placed, and the sleeve is perfect for a bladder.

The pack is easy to take on and off, easy to pack, and easy to get things in and out of when it counts. Nothing gets in the way. In a minimalist pack, that’s exactly what counts.

Best Uses

Of course, the Flash is an excellent daypack for most uses. If you’re hiking a fourteener, the Flash will do great. If you’re just biking around town, the Flash is a reliable companion.

But for most climbers, the Flash is an ideal value-buy for a multipitch pack. If you can do without a few bells and whistles, the Flash will be your lightest, cheapest, and often most versatile option. It’s been tested and approved by climbers around the country, and it continues to provide. Plus, for the price, you can get two Flashes for the price of one Patagonia version.

I’ve taken mine up multipitch climbs across the country, on all kinds of rock, in all kinds of weather. Not a single time has it let me down.

Click here to see the REI Co-op Flash 18 on

An alpine lead with the Flash 18
An alpine lead with the Flash


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