Rab Top Bag AR Review

An old favorite gets some important upgrades and stands out as a great value for an ultralight 30 °F sleeping bag.

Recommended

Overall Rating: Recommended

This is our third review of the Rab Top Bag, which is evidence enough that we like the concept and the bag. We're pleased to see that Rab followed our previous recommendations to make the pad sleeve fit a standard width sleeping pad, and to give the bag enough girth to accommodate side sleepers wearing extra clothing inside. However, the bag's new hood doesn't fully cover the head, and it's only useful for a back sleeper. Also, the bag is too short for hikers over 6 feet tall, so it's time to offer the Top Bag AR in both a regular and a long length.

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by Will Rietveld |

Introduction

One way to reduce weight in a sleeping system is to use a top bag or quilt. The original Rab Top Bag that we reviewed in 2001 was a trend setter, reducing weight by letting a sleeping pad serve as insulation for the bottom of the bag. In 2005, the bag was upgraded to the Quantum Qtop, which featured a Pertex Quantum shell and lining, but we were perplexed by its excessively wide sleeping pad opening (wider than a standard twenty-inch-wide sleeping pad) and tight girth. For spring 2008, Rab is rolling out another upgrade called the Top Bag AR; does this one get it right?

Rab Top Bag AR Sleeping Bag REVIEW Review - 1
The Rab Top Bag AR uses a sleeping pad for insulation on the bottom. Yep, the new version has a hood... well, sort of.

What's Good

  • Lightweight at only 20.5 ounces
  • 850+ US / 750+ EU down fill
  • Pertex Quantum shell and lining
  • Baffled construction
  • Well-designed pad sleeve fits a three-quarter or full length sleeping pad
  • Adequate girth for a side sleeper without compressing down

What's Not So Good

  • New "hood" is undersized and only useful for a back sleeper
  • Narrow or short sleeping pads do not provide complete bottom insulation
  • Four ounces heavier than its predecessor
  • Temperature rating is optimistic

Specifications

  Year/Model

2008 Rab Top Bag AR

  Style

Hooded top bag with bottom sleeping pad sleeve

  What's Included

Bag, stuff sack, storage bag

  Fill

7 oz (200 g) of 850+ US / 750+ EU fill power down, underside of footbox is insulated with 133 g/m2 Primaloft

  Measured Loft

1.75 in (4.5 cm) single layer loft

  Manufacturer Claimed Temperature Rating

30 °F (-1 °C)

  Stuffed Size

Measured dimensions: 14 x 7 in (36 x 18 cm).
Manufacturer specification: 9.5 x 4.3 in (24 x 11 cm).

  Weight

Measured weight: 1 lb 4.5 oz (581 g).
Manufacturer specification: 1 lb 2 oz (550 g).

  Sizes

One size fits to 6 ft (1.82 m)

  Fabrics

Shell and lining are 0.9 oz/yd2 (30 g/m2) Pertex Quantum with DWR

  Features

Sleeping pad sleeve fits three-quarter and full length pads, hood, elastic drawcord top closure, Primaloft insulation under the footbox, box wall baffles, stuff sack, cotton storage bag

  MSRP

$200 US

Performance

When the original Rab Top Bag came out, it was one of the few pieces of ultralight gear that could be purchased directly at the time. It wasn't perfect, as our previous reviews have pointed out, but we were glad to have it available because the alternative then was to make our own gear. Now there are many ultralight down sleeping bags available, and hikers are carefully comparing features and performance to choose the right bag for their needs. The market is much more competitive now, so has the new Rab Top Bag AR reached perfection or not?

To answer that question, let's start with the likes and dislikes from our 2005 review of the Quantum Qtop. We liked its light weight (16 oz), high loft down, baffled construction, and Pertex Quantum shell and lining. Those features haven't changed. We disliked the Qtop's extra wide sleeping pad opening (wider than a standard 20-inch-wide sleeping pad), tight girth, and only one length. The first two problems have been fixed, but the last one (multiple lengths) hasn't. Three new features have been added: the underside of the footbox is insulated with Primaloft, a sleeping pad sleeve has been added to the underside, and the bag now has a "hood."

Rab Top Bag AR Sleeping Bag REVIEW Review - 2
The underside of the new Rab Top Bag AR has a true pad sleeve made of Pertex Quantum fabric. It is fitted so a standard 20-inch wide sleeping pad (left), such as the Therm-a-Rest Prolite 3 Short (shown), fits snugly in the sleeve with no gaps on the sides to create cold spots. The sleeve has a clever extension (right) to accommodate a full length sleeping pad.

One thing to keep in mind is that the Top Bag AR does not work well with sleeping pads that are less than 20 inches wide and 48 inches long - such as the popular Bozeman Mountain Works TorsoLite. The TorsoLite is 17 inches wide at the top and tapers down to 12 inches wide at the bottom, so there are uninsulated gaps on both sides and the bottom end of the pad. The gaps won't be noticeable when sleeping at warmer night temperatures, but when the temperature falls below about 35 °F, the cold spots around the pad will be very noticeable!

Rab Top Bag AR Sleeping Bag REVIEW Review - 3
The new Top Bag AR adds a hood (left), or at least a partial one. The hood is not large enough to completely enclose the head, as modeled by my wife Janet (right), and is only useful to back sleepers.

The Rab Top Bag AR still comes in only one length, which I measured at 62.5 inches to the bottom of the hood opening and 72.5 inches to the top of the hood opening. Rab states that the Top Bag AR will fit a person up to 6 feet tall. I am 6 feet tall, and the bag is too short for me when I draw up the hood, though the length is adequate if I cinch the drawcord around my neck and do not use the hood (I simply fold it under my neck and wear a warm hat at night, like I would with a hoodless sleeping bag.). My estimate is that the Top Bag AR will fit a person less than 5 feet 10 inches tall using the hood. Interestingly, the previous hoodless model (the QTop) measures 69 inches long (I had the extra girth version), which is 6.5 inches longer than the new Top Bag AR. Go figure.

I found it difficult to measure the loft of the Top Bag AR because the insulated sides of the bag wrap around to the edge of the sleeping pad sleeve, causing the bag to stand up higher on the sides and sink in the center. My best estimate of single layer loft in the chest area is 1.75 inches. Rab estimates the temperature rating of the Top Bag AR at 30 °F, but it is not based an independent test according to the EN13537 standard (it's not possible to conduct a standard test and get a CE label on a sleeping bag with no insulation in the bottom).

As for weight, the new Top Bag AR weighs four ounces more than the previous QTop, which I assume is mostly due to the addition of a sleeping pad sleeve, hood, and Primaloft insulation under the footbox.

Rab Top Bag AR Sleeping Bag REVIEW Review - 4
Underside of the Rab Top Bag AR, head end (left), and foot end (right) with a full length sleeping pad.

Rab Top Bag AR Sleeping Bag REVIEW Review - 5
The Rab Top Bag AR comes with a roomy Pertex Quantum stuff sack. The stuffed bag measures 14 x 7 inches, but can be stuffed into half that volume if desired.

I field tested the new Rab Top Bag AR on a number of mountain backpacking trips in late summer and fall 2007 and spring 2008. In each case I slept in a single wall tent, with low temperatures ranging from 24 to 42 °F (measured with a Kestrel 4000 Weather Tracker). I consistently got chilly at about 35 °F and had to put on more clothing to stay warm the rest of the night.

I found the girth of the new Top Bag AR more to my liking than the QTop. While the previous QTop bag was too tight for side sleepers, especially in the hip area, the new Top Bag AR has adequate girth to accommodate side sleepers wearing lightweight insulated clothing inside the bag.

While our Backpacking Light Position Statement on Sleeping Bag Temperature Ratings emphasizes that there are many factors that affect a bag's warmth, I would like to present the following data to compare the Rab Top Bag with other popular ultralight down sleeping bags.

Manufacturer Model Temp Rating (°F) Single Layer Loft (in) Weight of Down (oz) Fill Power Total Weight (oz) Cost
Western Mountaineering SummerLite 32 2 10 850+ 19 $300
Marmot Hydrogen 30 ?* 10 850 21 $309
Montbell Super Stretch Down Hugger #3 30 ?* 10 800 23 $270
Feathered Friends Merlin 30 2 11.5 800+ 23 $314
Rab Top Bag AR 30 1.75 7 850+ 20.5 $200
    *At the time of writing, this information was not available.

As you can see from the table, a high quality baffled 30-32 °F down bag contains at least 10 ounces of high loft down, giving it about 2 inches of loft. The Top Bag AR is not insulated on the bottom, so that saves some down, but the loft is a bit deficient. That may explain my late night chills when the temperature dropped below about 35 °F, but isn't definitive. On the positive side, I had no problem staying warm down into the mid 20s °F in the Top Bag AR when I wore extra clothing, which was usually a Bozeman Mountain Works Cocoon Pullover and Pants.

Assessment

While I can't state that the Rab Top Bag AR has reached perfection, it certainly has come closer with its new sleeping pad sleeve that will snugly accommodate either a three-quarter or full length twenty-inch-wide sleeping pad. Using this bag basically commits a person to use a standard width sleeping pad in order to get a tight seal. An ultralight pad can be used in warmer temperatures, but it will have cold spots along the sides and end of the pad in colder temperatures. It would be nice to add another ounce of down to this bag to achieve a solid 30 °F temperature rating.

The girth of the new Top Bag AR is now adequate to accommodate side sleepers, but the bag's shorter length will be a deterrent to hikers at or over 6 feet tall. The hood provides some benefit to shorter hikers (it only partially covers the head), but it is of little use for taller hikers and side sleepers.

Finally, as seen in the above table, the Rab Top Bag AR is an excellent value at $200 for an ultralight sleeping bag, compared to the competition.

What's Unique

To save weight, the Rab Top Bag AR is not insulated on the bottom. Rather, it relies on a sleeping pad to provide insulation along the bottom of the bag.

Recommendations for Improvement

  • Offer the bag in regular and long lengths.
  • Add another ounce of down.
  • Re-design the hood to fully cover the head, so it can be drawn over the face.


Citation

"Rab Top Bag AR Review," by Will Rietveld. BackpackingLight.com (ISSN 1537-0364).
http://backpackinglight.com/cgi-bin/backpackinglight/rab_top_bag_review.html, 2008-06-03 00:00:00-06.

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Forum Index » Editor's Roundtable » Rab Top Bag AR Review


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Addie Bedford
(addiebedford) - MLife

Locale: Montana
Rab Top Bag AR Review on 06/03/2008 17:30:14 MDT Print View

Companion forum thread to:

Rab Top Bag AR Review

ROBERT TANGEN
(RobertM2S) - M

Locale: Lake Tahoe
Rab Top Bag on 06/03/2008 20:00:38 MDT Print View

Re: "One way to reduce weight in a sleeping system is to use a top bag or quilt." Really? Why then does the SummerLite weigh 1 and 1/2 ounces less?

Michael Davis
(mad777) - F

Locale: South Florida
Re: Rab Top Bag AR Review on 06/03/2008 20:16:05 MDT Print View

Good question, Robert! While I've tried to like the idea of a bottomless bag with a pad pocket, as Big Agnes and others have offered, they are not for me. I think if one sleeps like King Tut on a slab, they may be ideal.

But, I'm a side sleeping snuggler who likes to scrunch up my legs, etc. Therefore, my Western Mountaineering traditional mummy bags are the lap of comfort for me.

ROBERT TANGEN
(RobertM2S) - M

Locale: Lake Tahoe
Re: Re: Top Bag on 06/03/2008 20:43:22 MDT Print View

Preach it, brother Michael! To me, when I cram a pad into a top bag, it's like stringing a bow. Very un-natural feel.

Bob Bankhead
(wandering_bob) - MLife

Locale: Oregon, USA
Rab Top Bag AR Review on 06/03/2008 22:08:38 MDT Print View

Very important question - what is the maximum pad THICKNESS this bag will accept?

For example, the Big Agnes Insulated Air core is 2.5 inches thick. If a Thermorest Prolite 4 fits snugly, I have trouble envisioning how the BA could fit in there.

I'm a side sleeper so the previous comments are dead-on for me and makes this a no-go item. Back sleepers might like it, but all that air space with no decent neck seal means this thing is for really warm weather only.

Edited by wandering_bob on 06/03/2008 22:10:58 MDT.

Brian Macari
(BGMACARI) - MLife

Locale: Mid-Atlantic
Rab top quilt on 06/04/2008 05:56:54 MDT Print View

Assateague Island

The top bag concept works fine for side sleepers, which I am. You just have to shelf your fear of trying new stuff and figure out a methodology that works for you! I use a Backpacking Light UL 180 Quilt and I love it. It does cinch around the neck sealing up for heat retention.

Sven Klingemann
(svenklingemann) - F
Re: Rab top quilt on 06/04/2008 07:39:27 MDT Print View

Pretty disappointing stats/specs on the new bag. Price is not everything. I guess the golite adrenaline would be a better bet (though warmer).
S.

Brian Macari
(BGMACARI) - MLife

Locale: Mid-Atlantic
quilt on 06/04/2008 07:44:50 MDT Print View

How about the Golite Ultra quilt? Anyone used it? It seems to be out of stock constantly, so someone must be buying/using it out there!

Sven Klingemann
(svenklingemann) - F
Re: quilt on 06/04/2008 08:00:37 MDT Print View

I stand corrected - I meant the Ultra.

John S.
(jshann) - F
Re: Rab Top Bag AR Review on 06/04/2008 08:26:10 MDT Print View

I have not read this cuz I can't ..lol. I like the last version Quantum top bag (15 oz by my scale) alot. It's been my fav bag for several years now. I guess the bottom fabric could be a little more narrow, but it doesn't bother me. I put my pad outside my bivy since it is ccf. I don't really want a hood or the gross color of the new bag...or even a sleeve on the bottom. What's up with all these features..lol. Heck, I even bought a second RAB right before they changed to this new one. If colder than 32 degrees my go to bag now will be the golite ultra. It worked well enough for me into the lower 20s.

Edited by jshann on 06/04/2008 12:15:39 MDT.

Jason Brinkman
(jbrinkmanboi) - MLife

Locale: Idaho
Re: Rab Top Bag AR Review on 06/04/2008 10:34:21 MDT Print View

Maybe I'm a little jaded as a VERY satisfied Marmot Hydrogen owner, but I think you have overrated the Rab based upon the descriptions in this review... Recommended?!?

Seriously... not useful for anyone over 6 feet? Not for side sleepers? And only a half ounce savings over a full mummy bag from multiple manufacturers?

If I were to switch to a top bag, I would expect a half pound savings over my full mummy - not a half ounce!!

Please revisit your rating descriptions:

Above Average
Products that should meet consumer expectations, but against which other products in its class should also be considered.
[Sounds like what you said about the Rab to me.]

Average
Products in categories where better performance:weight and performance:value can be realized in several other competing products.
[I could definitely make a case here too if you want.]

You aren't seriously putting this in a class of it's own because it has a pad sleeve are you?

James Lantz
(jameslantz) - F

Locale: North Georgia
GoLite Ultra Quilt on 06/04/2008 20:23:36 MDT Print View

Brian,
I have used a long GoLite Ultra Quilt for 3 weekend trips on the AT in GA with temps ranging from 26 to 50 F. The bag was purchased for $250 in January 2008 & it weighs approx. 20 oz on my Taylor scale. I'm a back & side sleeper & am 6'1" tall & weigh 215 lbs.
The Ultra is plenty long enough for me & has enough girth to keep me covered when on my side. It has an enclosed foot box which comes up to the level of my knees. A Gossamer Gear torso length closed cell foam pad & Thin light pad are also my preferred accompaniments.
I was warm at 26 degrees in lightweight 2 piece polyester "long johns", thick Smartwool socks, & a fleece balaclava while in a tarptent. The Ultra's pad retention straps require correct positioning to keep you covered while needing to be loose enough to alow freedom of movement. This takes a little practice & to be honest, I wish the Ultra had the pad sleeve like the Rab AR as it would eliminate this learning curve & the inevitable air gaps with cold backside that come with it.
I would consider buying the Rab if it was longer & perhaps if it had a lower temp. rating. However, proper incorporation of clothing into the sleep system would solve this shortcoming. I hope this answers some of your questions & makes your decision a little easier.

Brian Macari
(BGMACARI) - MLife

Locale: Mid-Atlantic
golite ultra on 06/05/2008 05:04:10 MDT Print View

James, you should be doing reviews here! Outstanding. Thank you for the articulate overview. I am indeed closer, but they seem to be out of stock everwhere. Especially when they are ever available for a slight discount (typical 20% off deals). I have one of Golites old (like 5 or 6 years)20 deg top bags with velcro patches and it never quite felt comfortable, then i tried it with an insul-mat max-lite inflatable and the world got quiet at night. I have to say, I just upgraded from a Golite Gust to GL Pinnacle and with these tiny quilts, I am thinking of trying a Gossamer bag!

Brian Macari
(BGMACARI) - MLife

Locale: Mid-Atlantic
tarptent on 06/05/2008 05:10:59 MDT Print View

James, which model tarptent do you use? I use a cloudburst, and some friends complain about the breeze always coming through. Well heck, that is what i love most about the tent!

Dave T
(DaveT) - F
rab / jason. on 06/05/2008 09:57:46 MDT Print View

yep jason. i'm with you. i just can't see the utility of this bag, when compared to my wm caribou mf. it's a true 35 degree, weighs basically the same (21 oz in 6'6"), and has a full zip. unless you save lots of weight, i don't see the value vs. the limitations and fiddle/fuss factor. i don't get it.

Edited by DaveT on 06/05/2008 10:11:03 MDT.

René Enguehard
(ahugenerd) - MLife

Locale: Newfoundland
not worth it on 06/21/2008 14:47:51 MDT Print View

The main idea behind this bag is to remove all the insulation from the bottom since its not being used to save weight. However, somehow, it does great at the whole 'removing the insulation' thing and fails miserably at the whole 'saving weight' thing. I mean, the Summerlite is significantly lighter than this bag. What is on the go?

Moreover the amount of people turned off by this product since it mainly appeals to back sleepers is a big issue which is not at all mitigated by its low price-point. How can this be recommended? Maybe recommended under a very specific set of conditions, but even at that...

Peter Macfarlane
(ptc) - F

Locale: The Scottish Highlands
Rab AR on 08/17/2008 17:56:42 MDT Print View

I've got a preproduction Rab AR back in March of this year and on one trip using it in a bivy bag I woke up to find myself under snow cover and I was still warm in the bag, still fully clothed of course.
I use either Big Agnes or Exped 2.5" mats and they work fine, but in my sample it does pinch them in a little.
I don't think any coldness is due to the bag itself being deficient, it's more likely that the inherent cold spots you get in any top bag system are sucking the heat away.
It does have its limits, that's for sure. I won't be planning to sleep under snow in it again any time soon.

Frank Steele
(knarfster) - F

Locale: Arizona
Not for Side Sleepers? on 02/18/2010 08:06:36 MST Print View

I am not sure how this system, just like BA isn't for you side sleepers. I am a side and stomach sleeper and i love the top bag systems. When I roll over, the bag stays put, it doesn't roll with me, which drives me crazy. When I roll over or toss and turn in bed at home, the blanket stays put (I hate getting tangled up in a traditional bag). When I roll over in a top bag with a sleeve the bag stays put, just like at home. For me as a side/stomach sleeper a top bag with sleeve is the only way to go.

Lynn Tramper
(retropump) - F

Locale: The Antipodes of La Coruna
Re: Rab AR on 02/18/2010 13:09:59 MST Print View

I think it looks like a piece of doodoo! Recommended? We have been happily using the WM POD top bags for several years. With a minor adaptation to the sleeping pad attachment, the WM PODs blow the Rab away in all categories POD 30 weighs in at 430 grams and is conseravtively rated to 30F). Oh, and my partner is a satisfied side sleeper...

Here's a pic of the pad attachment. Just plain old velcro to mate with velcro glued to the bottom of the pads. Means it fits any size or thickness of pad. Shown here is 4oz torso-length RidgeRest:

POD bottom

Edited by retropump on 02/18/2010 13:11:22 MST.

Tyler H
(ctwnwood) - F

Locale: Utah
Rab AR - Any new feedback? on 08/09/2011 13:36:48 MDT Print View

I know this is a pretty old bag, but that's why it's on sale right now for $80. I'm wondering if there is any new feedback on this product, lots of negative vibes here which is fine if that's true consensus, just feeling it out again.

For me, price is huge. The argument that WM makes way better stuff doesn't really fly for me because I don't have anywhere near $300 to spend on a bag in the next 5-10 years. My next priority is weight, followed by warmth. Looking for a summer bag that can be extended with a down jacket, prolite and clothes.

Given that, and the fact that I sleep on my stomach, are there any new opinions on this?

Andrew Gustafson
(Gusty) - F

Locale: Southern Minnesota
Max Height on 08/27/2011 11:09:43 MDT Print View

I just got this bag on sale from Backcountry.com at $80. I haven't had a chance to try it in the field yet but in terms of it's max height I am 6' 140lbs and it fits me fine. I plan on using it as a summer bag (down to about 40 degrees). I'm able to keep my shoulders covered and cinch the draw cords around my neck if it gets too nippy. I wouldn't say I have any extra room but for a 20.4 oz. bag (measured on my digital scale w/out stuff sack) I am very happy. I wouldn't spend $200 on this bag because as others have said, there are much better options in that price range. But for $80 I couldn't find a better quality bag for the weight and temp. rating. If there are any still out there grab it.