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REI Flash 65 and REI Flash 50 Packs

Mini-review for the 2010 State of the Market Report on Internal Frame Backpacks.

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by Roger Caffin | 2010-09-28 00:00:00-06

To quote the REI website,"What began as a group of twenty-three mountain climbing buddies is now the nation's largest consumer cooperative with more than three million active members." That means that REI is a rare successful not-for-profit company: the profits made during the year are returned to the Members at the end of the year as in-store credits. In addition, REI has this apparently mad policy of allowing a no-questions return of any gear bought from them - cases of gear being returned years after purchase (and use) have been cited. You would think this would be commercial suicide, but that has not happened yet. Apparently the commercial advantages of giving potential customers that assurance outweighs the small number of cases where it gets exploited.

REI is obviously not a cottage industry by any means. Gear sold under the REI brand is not 'flash,' but they are usually solid functional items. It may be a case like that of the modern Toyota Corolla and an old Rolls Royce: the Corolla is reputed to have a higher quality. Why so? When you sell hundreds of thousands of something you get very good at eliminating the bugs. However, like several other American manufacturers, they were not that good at estimating pack volumes - at least, not according to the ASTM Standard.

REI Flash 65 Pack

Pack Rating Qualifications
Flash 65 Average Low cost, but not large

This pack was taken on a multi-day tour through some of the wilder parts of Wollemi National Park in Australia. It is a land of huge sandstone cliffs, dense basalt jungle, and some rather nasty (sharp and pointy) scrub. A pack needs to be fairly tough to survive in this country. In addition to carrying food for four days, I was carrying winter clothing, 4 L of water at times, and 40 m of light abseil rope (regardless, we didn't use the rope: 40 metres was too short for the cliffs).

REI Flash 65 and REI Flash 50 Packs - 1
REI Flash 65, 1.35 kg (2.98 lb), 50 L (3100 cuin)

I had no trouble fitting everything in the pack, provided I packed carefully. Only our flat foam sit-mats and the flat stove base went in the back pocket - it was convenient for that. A few bits went in the lid pocket. My camera was clipped to the shoulder strap. Otherwise everything else was inside. When I put the pack on at home, and also just out of the car at the start, I did notice that the padding down the back was very firm, almost hard. However, after about ten minutes walking up the hill, the padding and my back had become acquainted and got on well together for the rest of the trip, with no problems. It was noticeable that the pack did not carry 'heavy.' Sue found the lumbar pad on this pack to be 'male-oriented,' and it needed a bit more curvature for her, but this is normal.

As mentioned above, there is no way you could call REI a cottage industry company. This shows in several ways. First, there is some economy of features in the design, but I prefer to call that an absence of marketing frills (except for a stupid orange whistle buckle in the sternum strap). Since a mistake in the design could trigger a rather expensive recall, given the volume of sales at REI, there was obviously some incentive for the designers to get it right. I have to say they seem to have done that. Everything worked quite well.

Technically, the internal frame consists of a stiff plastic sheet and two aluminium stays. You can get the aluminium stays out to alter the bends if you want. The two rectangles of padding contain highly perforated foam covered by soft nylon mesh. The shoulder straps and hip belt are also mesh over foam. The straps are all long enough and the buckles worked very reliably. The waterproof zips on the lid and the back pocket are a bit stiff to open, but that applies to all WP zips. The fabric is light, but apart from getting a trifle dirty in the scrub, it survived the trip without any visible effects. And the base of the bag is fairly square, so the pack sits upright.

There is a small security pocket attached to the strap under the lid with a hook&loop closure. I was not entirely convinced about the idea, but it worked just fine. I could have used the much larger security pocket on the underside of the lid - it is also closed with hook&loop tape, but for what I wanted (credit card, drivers licence, keys) the latter seemed too big.

There are compression straps under the base of the pack. You could use them for carrying a rolled-up foam mat of course, or you could reduce the volume of the bottom half of the main bag. Both work. There are lots of other little attachment points on the bag, but I haven't needed any of them.

REI was not happy with the volumes we measured for either of the Flash packs. Their measurements gave quite different results, as the table shows. However, since so many other manufacturers' claims came out within a few percent of our measurements, we are confident of our methodology and that we comply reasonably well with the ASTM Standard. During the email discussion which ensued, we were told that REI had measured the capacity of the lid pocket to be 9 L: we had measured it as 4 L. REI had measured the back pocket as having a capacity of 6 L: we had found it was very difficult to get anything much into it without pushing back into the main bag. In fact, in the field all I was able to get into the back pocket was two small sit-mats, and that took a bit of pushing. The only way we could get the volumes quoted by REI into those two pockets would be to fill them up while the main bag was empty, but this is not how a walker uses a pack. We do not have an answer here.

REI Flash 50 Pack

Pack Rating Qualifications
Flash 50 Average Low cost, but not large

You could call this the smaller brother to the Flash 65. I did manage to get all the test gear inside the bag, but I had to float the lid up a bit to get it to cover the tent. The strap under the lid, which I used to hold the tent in place, is combined with the strap which holds the back pocket. I was not really enthused about this design: I would prefer they added an extra buckle.

REI Flash 65 and REI Flash 50 Packs - 2
REI Flash 50, 1.18 kg (2.60 lb), 43 L (2600 cuin).

Once again, the harness or back padding was really solid. Sue found this fitted her OK and was quite comfortable with it. As might be expected, it too carried fairly 'light.' The upper part of the main bag is noticeably straight up rather than tilted towards the wearer's head. A bit of a tilt at the top could be created by bending the aluminium strips, but note that the bag design is straight. You could not put much bend in without distorting the bag.

This pack seemed a bit better shaped for a woman, with just a bit more curvature at the lumber region. Whether this would be found with every unit I do not know, but you can always adjust the curvature to suit anyhow. That's the great thing about the use of aluminium stays down the frame: they can be shaped to suit the wearer.

The shoulder straps had a lot of extra length to them. I have yet to understand why pack makers seem to have so much trouble getting shoulder straps and sternum straps the right length - a bit of extra length but not too much. However, that is a minor point.

A curious thing found on both Flash packs is what looks like double side pockets. As you can see from the photo, there seems to be a tall flat side pocket with a shorter bulging side pocket over it. Actually, the short bulging side pocket is real, but the tall flat 'pocket' is actually the mesh sides to the back pocket. Yes, you could use them as 'pockets', but I doubt you could get much in them. The same applies to the zipped pocket on the outside of the back pocket: it is a bit flat and of limited value. It is strange that REI have these two 'features' on the Flash when removing them could lower the cost. The back pocket itself does not have a lot of space either, but it was useful for carrying our flat sit-mats.

This is a mini-review in the 2010 Lightweight Internal Frame Pack State of the Market Report. The articles in this series are as follows (mini-reviews can be found in Part 2), and a subscription to our site is needed to read them.

  • Part 1A covers the very basics and lists all the packs in the survey.
  • Part 1B covers the frame and harness which carry the pack itself.
  • Part 1C covers the main bag and all the other pockets, plus the all-important question of comfort.
  • Part 2 in this series covers the individual packs tested.


"REI Flash 65 and REI Flash 50 Packs," by Roger Caffin. (ISSN 1537-0364)., 2010-09-28 00:00:00-06.


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Lightweight Internal Frame Packs: a State of the Market Report - Part 2: The Packs
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Coin Page
(Page0018) - MLife

Locale: Southeastern USA
External Frame Packs? on 10/18/2010 20:47:02 MDT Print View

Thanks for a nice review Roger.

Perhaps outside the scope of this review, but since the subject of external frame packs has come up: do you have any recommendations for lightweight, commercially available, external frame packs that capture your "H - frame" idea?

Back in the old days, my external frame pack and hip belt could shift almost all the weight onto my iliac crests, or alternatively, onto the greater trochanters.

I find now, with increasing age, a decreased tolerance for prolonged heavy loading of the L5-S1 disk, and the SI joints. Anything much over 20 lbs all day, no matter how it's distributed over the shoulders or the lumbar area, starts to hurt.

Some of the individual pack reviews and comments above suggest some of these packs come close, but it sounds like you think the external frame is better at overall comfort - issues of durability, fragility and standing up to heavy brush aside.

Am I on the right track here? Any advice. How can I get most of the load back on the sides of my hips - the iliac crests - and still go lightweight?

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: External Frame Packs? on 10/20/2010 23:43:42 MDT Print View

Hi Coin

Sorry, but I don't have a simple answer for you. I think I noted somewhere in the review that my hips are rather narrow, such that many hip belts do not work very well on me. For this reason I have always preferred to carry the load on my back. This does *not* mean 'on my shoulders'.

With my design I find the load does go through the mesh on the back of the pack to the full area of my back. Frankly, I am not really sure why this works so well, but it does work for me.

I am sure that it won't work for many other people, and that a solid hip belt will work better for them. In this sense, fitting a pack to a person is very much like fitting a pair of shoes. I sigh (for the same reason) when I see someone ask 'what shoes should I buy' and then read a reply that they should buy SuperDucksMultiWeb shoes.

However ... I will offer the following advice - which is also in the Review somewhere. Try to buy a pack which matches your torso length, but do not buy a pack with a torso length which is too short. Better to have a pack torso length slightly longer than your torso length: that will throw the load onto your hips more effectively.

Even better: pick a pack in the right size with an adjustable torso length. Then fine tune over several trips how it fits you. Yes, I definitely give brownie points to packs with an adjustable torso length.

I also give brownie points to packs with a solid stiff harness or frame. Frameless packs are all very well if my total load is under 6 -8 kg. Over that the weight of the harness is far outweighed by the added comfort it brings. Now, I know this comment will attract numerous responses contradicting me and saying how wonderful a frameless pack is. Well, as with shoes ...

Can an external frame pack (like mine) stand up the 'heavy brush'? Chuckle. Trust me, the scrub in the Australian Blue Mountains (and in SW Tasmania) is definitely world class.

A commercial equivalent? Sorry - at this stage I cannot make a recommendation, because I don't know.


Cameron Semple
(camS) - F

Locale: Brisbane, Australia
Shadow on 10/21/2010 06:43:52 MDT Print View

I had a look at a Shadow this evening at a local distributor. I liked the clean, no frills look. Didn't have time to load it up though. You mentioned the thick webbing used on the hip belt. I found it virtually impossible to tighten the belt once fitted. The webbing was so rough that it wouldn't pull through easily. Combined with the older style of pulling the straps out rather than into the middle.

Any ideas when the 2011 line of packs will be available? The Umbra looks interesting.

Edited by camS on 10/21/2010 06:45:49 MDT.

al b
(ahbradley) - M
small manufacturers / osprey atmos on 10/21/2010 15:46:43 MDT Print View

Roger (Caffin):
Would any of the ultralight small manufacturers be interested in making your external frame sacks.

The osprey atmos 50/65 has a kind of all back mesh (for ventilation) but I think the gap between back and pack is bigger. I didnt like the shooulder straps.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: small manufacturers / osprey atmos on 10/21/2010 20:58:46 MDT Print View

> Would any of the ultralight small manufacturers be interested in
> making your external frame sacks.

I would be delighted if someone did want to.


al b
(ahbradley) - M
osprey exos possible equiv to Roger (Caffins) MYOG external frame on 10/22/2010 04:55:27 MDT Print View

Roger (Caffin):

Actually, from reviews, the osprey exos 46/58 looks better than the atmos, as still has kind of all back mesh (for ventilation) but the gap between back and pack seems smaller, and the rucsac storage looks less curved.

Perhaps you could borrow one and compare it (not using waist belt) against your external frame pack.

Coin Page
(Page0018) - MLife

Locale: Southeastern USA
External Frame Packs? on 10/24/2010 09:12:13 MDT Print View

Thanks Roger.

Yes, like finding well fitting shoes. But I did find those (wider), so I keep my optimism for finding the perfect pack for heavier loads. Thanks for the reminder/emphasis on torso length (longer for me).

The Aarn packs, and LuxerLite pack seem hopeful. Discussions of these packs over the last 5 years give lots of opinions both ways. I would love to hear from owners/users of these packs what they still think of them now.

Any other packs in this general class - lightweight with enough frame to transfer all the weight to my hips if I want to - that anyone thinks I should also consider? Any packs in the review above come close for a long torso?


Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: osprey exos possible equiv to Roger (Caffins) MYOG external frame on 10/24/2010 15:35:08 MDT Print View

Hi Alan

The survey covered both the Exos 46 and the Exos 58. Nice packs.


Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: External Frame Packs? on 10/24/2010 15:38:09 MDT Print View

Hi Coin

The survey lists the available pack sizes. I was testing Medium in just about everything, but many of them have a Large model available.

Which one to choose? Ahhh... Very personal. 'Every body is subtly different ...' as they say on the planes.


Lynn Tramper
(retropump) - F

Locale: The Antipodes of La Coruna
Re: External Frame Packs? on 10/25/2010 12:46:16 MDT Print View

"The Aarn packs, and LuxerLite pack seem hopeful. Discussions of these packs over the last 5 years give lots of opinions both ways. I would love to hear from owners/users of these packs what they still think of them now."

I have used both of these, and in both cases they are nice packs, but I ended up using them without the front pockets. They just didn't work for me. however, if you like front pockets, I find the LuxuryLite pocket (and frame) to be more functional and cooler. I also ditched the LuxuryLite cylinders and modifies a GoLite Gust to attach to the frame. Excellent volume and comfortable carrying. Note: the LuxuryLite pocket restricts you vision more than the Aarn. Also note, I have both of these for sale. If you are interested, shoot me a PM and we can negotiate a price.

eric chan
(bearbreeder) - F
frogs ... on 10/26/2010 06:24:59 MDT Print View

just a note for others that the french site i-trekkings has done a similar test with packs in roughly the same weight and volume range

note how the Decathlon Forclaz 50 Ultralight scored very high in comfort and on score/price while being the cheapest and lightest pack

just shows you what can be done ..

just use google translater on the links below

Edited by bearbreeder on 10/26/2010 06:28:48 MDT.

al b
(ahbradley) - M
exos 58 usage with no load thru hip belt on 10/27/2010 15:08:48 MDT Print View

Roger (Caffin):

I checked the articles 1A-C,2 butt did not find a mention of testing the exos 58 with no load bearing via the hip belt i.e. a comparison against the way your your external frame myog pack is used.

Do you still have one for a hip-beltless comparison against your external frame pack.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Re: exos 58 usage with no load thru hip belt on 12/16/2010 20:22:34 MST Print View

Hi Alan

Sorry, this dropped off the radar for a while.
Unfortunately no: the Exos packs were farmed out to Australian readers.


Eric Botshon
(Ebotshon) - F
Exos 46 on 07/12/2011 10:36:03 MDT Print View

The review mentioned that the osprey pack was closer to 40 than 46 liters.

Any chance this test was done with a size small pack instead of the medium? The smal torso length pack is smaller than the stated 46.

Willem knopper
(willem65) - MLife
Exos Frame on 09/08/2011 15:41:10 MDT Print View

I have tried the Exos and I find them to be to very ridged, the pack does not move with you (back) at all. I personally think they are really just a fancy external frame pack. I did like the idea of the air flow but was just very disappointed how it restricted your movement especially if you were to use it doing any walking other than on the flat.


Phillip Damiano

Locale: Australia
Jansport Big Bear on 03/22/2012 21:42:44 MDT Print View

Roger mentioned in one of his comments here:
(Yes, we kept a few, for specific functions. The rest have been passed on to Australian & NZ BPL members (kept the postage down) for further field testing. I expect that they will provide some Reader Reviews in due course).

I'm one of those Australian BPL member, I've recently acquired one of the Jansport Big Bear 63 prototype packs of Roger.
The pack has only been in my possession for a few weeks now, tested on day hikes including some rock climbing.
The Harness is very comfortable and the material is very durable. I've tested this on a Off-track hike recently with very thick vegetation. I got scratches over me, the pack survived with no scratches.

I'm yet to test it out as a Overnight hike, but I can't see it causing any problems there. It's a nice pack. I do like the colour that the prototype pack was supplied in with the orange trims.

This is an on going review, I will keep you's updated on my findings on my next overnight hike, which is not for another 3 weeks from today. In a couple days, I've got a day hike I'm planning on, I will pack all my overnight hiking gear into the pack for a test to see how the pack feels with some weight in it. My base weight is just under the 8Kg. I'll add a few litres of water to that, making a total weight of 11kg.

So far, I like the pack. It's not exactly on the ultra light weight at just under 1.5kg but it does have a good frame and harness.Jansport Big Bear Prototype Pack

Edited by Phillipsart on 03/22/2012 21:51:42 MDT.

Phillip Damiano

Locale: Australia
Re: Jansport Big Bear on 03/24/2012 19:33:34 MDT Print View

Packed my hiking gear into the Jansport Big Bear pack yesterday and went for a walk around the block with apx 12kg load. Pack is comfortable, enough room for 5 or 6 days of food. No complaints.

Will be continuing wearing the pack with my gear on daily hikes for the next couple of weeks as training for an upcoming 3 day overnight hike in some steep terrain.

Eric Blumensaadt
(Danepacker) - MLife

Locale: Mojave Desert
"Pocket Man" on 06/14/2012 21:41:39 MDT Print View

I own an older - and IMHO better - version of the REI Flash 60. It's the REI Cruise UL 60 (2nd model). That pack absolutely NEEDED side pockets. Fortunately REI had "aftermarket" pockets at that time, but no longer.

I like side pockets because they store stuff I may need quickly like 1st aid kit, water treatment kit, toilet kit, potty kit, and things I don't want inside my pack
Like stove stuff including fuel. (For ex., ESBIT tabs smell fishy -like two other things I know of. ;O)

My REI pockets add 400 cu. in. each and make the pack "complete" in my dinosaur mind. Yeah, I'm a geezer and like exterior pockets. As another poster said of the Ospey EXOS that front "shovel" pocket is nice and can hold that wet tent, etc. Same goes for my Cruise UL 60 - which should really be called the "UL 50" - sorta like many post-recession 401-K funds should really be called "201-K" funds.

SPIRIDON Papapetroy
(spotlight) - F
Osprey Exos on 09/09/2012 21:15:47 MDT Print View

Has anyone had pain in the part of the body where the lower part of the frame touches it. I am a bit worried because it doesn't have any padding.

Phil Cawley
(Philc) - M
Lightweight Internal Frame Packs. on 04/08/2015 21:50:37 MDT Print View

Hi, First time I've ever made comment. In my mind (without a doubt!) everything considered Aarn Packs are the way to go! I've got four of them (one for nigh on every occasion!) and would NEVER consider going back to the old style! Try 'em and you'll use 'em. Phil.