Even though the REI Co-op Flash 18 isn't explicitly designed for rock climbing, we included it in this review because it's popular, and our daypack testers suggested we give it a shot. We're glad we did too, because this pack fulfills most of the roles of a rock climbing daypack, but at less than half the price of the other options. At just 10 oz, the Flash is the lightest weight pack we tested and compresses down tightly to be stuffed inside a crag pack or overnight rucksack. The ideal use for the Flash is on straightforward multi-pitch routes. Its low weight and simplicity make it perfect for long face climbs or moderate splitter cracks.
For these reasons, it took home our Best Buy award. Take care though, because its low weight comes at a cost in durability; the 140-denier nylon it's made of is fragile and susceptible to abrasion. However, with a low price tag, many shoppers may be able to overlook these deficiencies. We recommend this bag to casual climbers searching for an affordable multi-pitch daypack, just be sure to avoid chimneys or hauling.REI Co-op Flash 18 Review

Cons: Fragile, wimpy shoulder straps
Manufacturer: REI
Our Verdict
Compare to Similar Products
![]() This Product
REI Co-op Flash 18 | |||||
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Awards | ![]() | ![]() | ![]() | ||
Price | $40 List | $78.95 at Backcountry | $69.95 at Amazon | $59.95 at Backcountry | $79.95 at Amazon |
Overall Score ![]() |
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Star Rating | |||||
Pros | Lightweight, cheap, ice axe loop | Simple, great zippered pocket, streamlined | Comfortable, easy to pack | Simple, sturdy, light | Light, great features, roomy |
Cons | Fragile, wimpy shoulder straps | Limited attachment points, easy to drop stuff | Heavy, below average durability, no emergency whistle | No emergency whistle, draw cord and cord lock blend into pack | Fragile, not super versatile |
Bottom Line | This model isn't very durable but it also isn't very expensive; it's also quite light | Though there are no extra features, this bag ticks the boxes for mulit-pitch climbing | Comfortable, excellent packing volume for a sleek looking pack | This well rounded pack is a good choice for long rock climbs | Alpine climbing mission? This is the small pack for you |
Rating Categories | REI Co-op Flash 18 | The North Face Route Rocket | Petzl Bug | Black Diamond Rock Blitz 15 | Black Diamond Blitz 20 |
Comfort (25%) | |||||
Climbing Utility (25%) | |||||
Durability (20%) | |||||
Versatility (20%) | |||||
Weight (10%) | |||||
Specs | REI Co-op Flash 18 | The North Face... | Petzl Bug | Black Diamond Rock... | Black Diamond... |
Capacity (Liters) | 18 | 16 | 18 | 15 | 20 |
Measured Weight | .6 lbs | 1.1 lbs | 1.1 lbs | 0.85 lbs | 0.88 lbs |
Padded back? | Yes | Yes | Yes | Yes | Yes |
Fabric Type | 140D nylon | 420D nylon | 400D nylon | 840D nylon | Dynex (210D + PE 200D) |
Whistle? | Yes | Yes | No | No | No |
Accessory Pockets? | One external zip, two internal open | One external zip | One external zip, one external open, one internal zip | One external zip, one internal zip | One external zip, one internal zip |
Outside Carry Options? | Daisy chain and ice axe loop | External daisy chains | Top strap, one daisy chain | Top strap doubles as rope strap | Top strap, ice axe attachments |
Hip Belt | Yes, removable | Yes, removable | Yes | Yes, removable | Yes, removable |
Hydration System Compatible | Yes | Yes | Yes | Yes | Yes |
Key Clip? | Yes | Yes | Yes | Yes | Yes |
Our Analysis and Test Results
We hesitated to include this pack in the rock climbing daypack review because it's not designed specifically for rock climbing. However, the popularity of the Flash 18 at the cliffs and among our climbing testers forced us to consider it. In the end, we were impressed with how useful it is and the significant value it offers.
Performance Comparison
Weight
The Flash 18 is the lightest pack in the rock climbing daypack review, at 10 ounces (283 grams). The next lightest pack in our test weighs a few ounces more. That difference could let you carry an extra runner or quickdraw, or more snacks.
For these reasons, the Flash is our favorite choice for difficult face climbing routes without chimneys or hauling. Minimalists can cut the total weight an additional 2.5 ounces, by removing the foam back pad, hip belt, and sternum strap.
Durability
Durability is this pack's greatest weakness. It is made primarily of 140 denier, polyurethane-coated, ripstop nylon. This is substantially weaker than the fabrics of many of the other packs in our review. The ripstop checkerboard pattern does help prevent tears from spreading but doesn't add any abrasion resistance. The polyurethane coating is supposed to bolster abrasion resistance but is also included on other packs we tested, so it isn't a unique advantage. This pack has a thin grab loop, and we'd hesitate to trust hauling from its thin shoulder straps for very long. Although those shoulder straps are the most ventilated, they're also the most fragile.
If you strictly use this pack for face climbing, it should survive. Beware of chimneys, laybacks, offwidths, or any other pitches where it might scrape along the rock. When packing, we'd recommend you do not place anything firm against the fabric, like approach or climbing shoes, as this could exacerbate wear and tear. We suggest anyone who prefers to haul their daypack on strenuous pitchest to select a bag that's designed with this in mind.
Climbing Utility
Although this pack is not intended specifically for rock climbing, it has many features we like in a climbing daypack. Like the many of the packs we tried, it is hydration system compatible. It has a zippered external accessory pocket that can be a little tricky to use when the pack is at max capacity. It also has two internal drop-in pockets (one with a key clip) that are a good size for a headlamp or candy bars. Its back pad, hip belt, and sternum strap are also all removable to customize it to your needs. Additionally, the sternum strap buckle doubles as an emergency whistle—a safety feature we wish was included on all rock climbing daypacks.
Our testers all think this pack is a great size for holding most things we need on a multi-pitch outing (including approach shoes) without undue difficulty. The Flash has a relatively sleek exterior. Our testers found as long as they were careful to tuck the drawstring into the pack there was minimal snagging.
It loses points in climbing utility for a few reasons. There are a few possible configurations for hauling—you can clip a carabiner to the grab loop, through the hydration hose port, or the daisy chain—but none of these locations are particularly strong. Besides, it's unlikely the 140d nylon body could withstand much hauling. This cost it a few points in the climbing utility category.
Versatility
Within rock climbing, the uses of the Flash are fairly limited; it's only tough enough to handle straightforward multi-pitch routes without hauling or high abrasion potential. Outside of rock climbing, this pack's uses are almost limitless. The thin fabric isn't a problem for low abrasion activities like hiking, mountain biking, or skiing.
This pack is also small and compact, making it extremely packable. You can turn it inside-out and use it as a stuff sack inside a larger overnight backpack. After setting up camp, turn it back to right side out and use it as a daypack for backcountry adventures. It was the best pack in our test for this purpose. The light, simplistic design was appreciated by our testers for casual urban occasions as well.
Though many of the packs in the review can be rigged to carry an ice axe, this is one of only a few models with a built-in ice axe loop. However, it can only comfortably hold one ice axe, limiting its alpine utility. It also lacks practical external carry options. Though the eight pocket daisy chain can be used to attach things to the pack, it is challenging to meaningfully secure those items.
Comfort
Some of the suspension system's qualities on this pack make evaluating its comfort difficult. The ventilated shoulder straps are more breathable than any of the others we tried, but they're also thin, offer little padding when carrying a heavy load and easily roll and twist. Although we like that its foam back panel is removable, the foam is flimsy and not very useful as a 'sit pad', as REI suggests.
When actually on the rock (and if loads were modest) our testers think this pack is quite comfortable. Many didn't notice they had it on - under those circumstances. Overall, this award winner is comfortable with small, malleable, loads but can get unpleasant when asked to carry anything heavy or pointy.
Value
The biggest reason to consider the Flash is the price tag. It's less than half the price of many of the other packs in this review. We've even seen this pack on sale for as low as $25. Let your climbing habits guide your purchasing decision though. Many climbers don't climb multi-pitch routes all that frequently, and when they do, they usually don't carry a pack every time. We also know most climbers hate chimneys and avoid hauling at all costs. Therefore, many shoppers probably don't need a pack as strong as some of the high-end options. Try to calculate how often you will use a climbing daypack and whether it's worth spending the extra money for a premium bag, or saving it on the functional but delicate Flash.
Conclusion
Lighter and lighter climbing gear is all the rage today and was one reason we liked the 10 oz Flash so much. It fulfills all the roles of a daypack, transporting 18 liters worth of gear comfortably within a compact space. The primary weaknesses are durability and the absence of a strong haul loop. Although dedicated adventure climbers are probably better off with one of the sturdier climbing daypacks, most casual multi-pitch climbers will be happy with the Flash 18, and we're pleased to give it our Best Buy award.
— Ian McEleney