Reviews You Can Rely On

REI Flash 45 Review

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rei flash 45 ultralight backpack review
Credit: REI
Price:  $160 List
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Manufacturer:   REI
By Brandon Lampley ⋅ Review Editor  ⋅  Jan 31, 2016

Our Verdict

The REI Flash 45 is one of the most affordable packs we tested, but it unfortunately performed so poorly we have a hard time recommending it over much higher performing competitors. The weight-to-volume ratio is poor and the very flexible simple frame does a poor job transferring weight to the waist belt. On the plus side, it is cheap.
REASONS TO BUY
Cheap
Lots of external storage
REASONS TO AVOID
Mediocre carrying comfort
Poor weight-to-volume ratio
Poor design for main pack pocket
The Flash competes most closely in volume and features with the three highest scoring overall models. The Editors' Choice Gossamer Gear Gorilla and the Best Buy Osprey Exos 48 are both much better packs.

Our Analysis and Test Results

The REI Flash 45 earned below average scores in all of our metrics with the exception of features. It includes a lot of our favorite pockets and straps, but with interesting and not always useful departures from common construction.

Performance Comparison


rei flash 45 ultralight backpack review - logging some miles with a 25 pound load in rocky mountain national...
Logging some miles with a 25 pound load in Rocky Mountain National Park.
Credit: Brandon Lampley

Weight-to-Volume Ratio


This pack is available in medium and large torso lengths; our test model was the large version, which was appropriate for our 5' 11" lead tester.

rei flash 45 ultralight backpack review - the flash's exterior pockets hold a lot of volume, but can dump out...
The Flash's exterior pockets hold a lot of volume, but can dump out your gear when you disconnect the straps to access the main bag.
Credit: Brandon Lampley

Unlike all the other packs we tested, the side and front pockets on this pack are not separated, but rather form one large, continuous mesh storage pocket. More about this below in features. At 20 g/L for both max and stripped of its lid, the Flash earned one of the worst scores for average weight-to-volume ratio. Even the more fully featured Exos 48 has a better ratio.

Load Carrying Comfort


This product didn't overly impress us in carrying comfort; we judged it "Good" at carrying both 15 and 30 pound loads. The flexible Delron rod that forms the side frame doesn't function as well as more rigid minimalist frame systems for stabilizing your load.

rei flash 45 ultralight backpack review - the flash accepts this 25 pound load with room leftover, but doesn't...
The Flash accepts this 25 pound load with room leftover, but doesn't carry it that well.
Credit: Brandon Lampley

Features


The Flash 45 is one of the most featured models we tested, with some strange departures from common construction. The main pack closes with a simple drawstring and is topped with a removable floating lid. Unlike all the other packs we tested, the external storage is one large wrap-around mesh pocket. At first glance, it appears to be two side pockets and a main front pocket, but no, it's actually just one big external pocket. We found it hard to get our water bottles to stay put on the side. There are no lower compression straps on this pack, just one on each side near the top.

The Flash has a large free-hanging pocket inside that accepts a hydration bladder and a mitten hook on a sewn-in loop at the top to secure it. You'll find a port that allows for use of a drinking hose.

rei flash 45 ultralight backpack review - a shoulder strap pocket is one of the awesome features on the flash...
A shoulder strap pocket is one of the awesome features on the Flash. However, we did not find the unique side pocket construction beneficial.
Credit: Brandon Lampley

Adaptability


This pack earned a low adaptability score. While there are side compression straps and exterior lash options, we found them not very useful. If you need to get into the main pack, you must disconnect at least two of the buckles that are likely holding your externally stored gear in place. It's possible to dump your whole exterior load just because you need one item from inside the main pack. In addition, no lower compression straps mean that low volume loads carry poorly by filling the bottom of the pack.

rei flash 45 ultralight backpack review - without compression straps for the lower portion of the main bag...
Without compression straps for the lower portion of the main bag, smaller loads carry awkwardly, filling the bottom and leaving the upper portion of the pack empty.
Credit: Brandon Lampley

Durability


The Flash 45 earned a low score for durability. We'd recommend the Gorilla or Hyperlite Mountain Gear Windrider 3400 if you want a similarly sized pack that is more durable.

Best Applications


This REI backpack is not the best pack for any niche we can think of. Our three award winners each fit a niche along the ultralight backpacking spectrum.

Value


This bag is often on sale at up to half of its retail price. If your budget is very limited, it'll get the job done til you can save up for something better.

Conclusion


With a poor weight-to-volume ratio and the least utilitarian set of features, the REI Flash 45 scored at the bottom of our field of contenders.

rei flash 45 ultralight backpack review - if it's all you can afford, the flash will get the job done...
If it's all you can afford, the Flash will get the job done. However, we'd recommend saving up for a better performing ultralight pack.
Credit: Brandon Lampley

Brandon Lampley