Reviews You Can Rely On

Rab Neutrino 400 Review

A lightweight and high-quality sleeping bag that's just a step behind our favorites
Rab Neutrino 400
Credit: Rab
  • 1
  • 2
  • 3
  • 4
  • 5
Price:  $400 List | Check Price at REI
Compare prices at 3 resellers
Pros:  Lightweight, thoughtful design, effective neck baffle
Cons:  Expensive, narrow foot dimensions, annoying drawcords
Manufacturer:   Rab
By Jack Cramer ⋅ Review Editor  ⋅  May 26, 2022
Our Editors independently research, test, and rate the best products. We only make money if you purchase a product through our links, and we never accept free products from manufacturers. Learn more
69
OVERALL
SCORE


RANKED
#9 of 20
  • Warmth - 20% 8.0
  • Weight - 20% 7.0
  • Comfort - 20% 7.0
  • Packed Size - 15% 6.0
  • Versatility - 15% 6.0
  • Features & Design - 10% 7.0

Our Verdict

There are plenty of things we like about the Rab Neutrino 400. It's lightweight and packs down small. The well-designed draft collar wraps 360-degrees around your neck to seal in heat when temps drop to the bag's 20F temperature rating. At the same time, the 3/4-length main zipper offers acceptable venting during warmer conditions. We also love that Rab chose to include recycled materials for the outer shell and internal lining. Despite all the positives, when we compare the Neutrino 400 directly with other high-end sleeping bags, it can't quite keep up. The 850FP and 900FP down found inside other bags simply out insulate the 800FP down in this bag. The Neutrino 400 is an excellent backpacking sleeping bag, but at full price, we have to give the edge to a few other models.

Compare to Similar Products

 
Rab Neutrino 400
This Product
Rab Neutrino 400
Awards  Editors' Choice Award  Best Buy Award Best Buy Award 
Price Check Price at REI
Compare at 3 sellers
$520.00 at Backcountry
Compare at 2 sellers
$330.70 at Amazon
Compare at 2 sellers
$235 List
$235.00 at REI
$100 List
$99.95 at REI
Overall Score Sort Icon
69
80
73
63
52
Star Rating
  • 1
  • 2
  • 3
  • 4
  • 5
  • 1
  • 2
  • 3
  • 4
  • 5
  • 1
  • 2
  • 3
  • 4
  • 5
  • 1
  • 2
  • 3
  • 4
  • 5
  • 1
  • 2
  • 3
  • 4
  • 5
Pros Lightweight, thoughtful design, effective neck baffleSpacious dimensions, super comfortable, great loft, lightweight, made in the USASpacious hourglass shape, innovative venting "gills", waterproof footbox, sturdy compression sackDecent weight, respectable warmth, awesome bargainGreat price, respectable weight, simple design
Cons Expensive, narrow foot dimensions, annoying drawcordsExpensive, awkward hood, good but not great zipperBelow average warmth-to-weight ratio, bulky packed sizeAverage materials, limited features, basic designSubpar warmth, annoying hood drawcords, no storage sack, mediocre versatility
Bottom Line A lightweight and high-quality sleeping bag that's just a step behind our favoritesThe best ultra-premium bag that combines warmth, low weight, good packability, and luxurious comfortPremium down in an hourglass shape that offers the roomiest lower body dimensionsAn exceptional deal for a capable and sturdy backpacking sleeping bag for those looking to get outside without breaking the bankAn acceptable sleeping bag at a rock bottom price
Rating Categories Rab Neutrino 400 Western Mountaineer... NEMO Riff 30 Mountain Hardwear B... REI Co-op Trailbrea...
Warmth (20%)
8.0
8.0
4.0
6.0
5.0
Weight (20%)
7.0
8.0
7.0
6.0
3.0
Comfort (20%)
7.0
9.0
9.0
6.0
6.0
Packed Size (15%)
6.0
8.0
8.0
8.0
5.0
Versatility (15%)
6.0
7.0
8.0
6.0
7.0
Features & Design (10%)
7.0
7.0
9.0
6.0
6.0
Specs Rab Neutrino 400 Western Mountaineer... NEMO Riff 30 Mountain Hardwear B... REI Co-op Trailbrea...
Insulation 800 FP Down 850+ FP Down 800 FP Down 650 FP Down Synthetic - Polyester
Compressed Volume 8.9 liters 7.2 liters 7.2 liters 7.5 liters 9.8 liters
Measured Bag Weight (Size Long) 1.91 lbs. 1.62 lbs. 1.91 lbs. 1.98 lbs. 2.74 lbs.
Manufacturer Claimed Weight (Size Regular) 1.84 lbs. 1.50 lbs. 1.80 lbs. 1.79 lbs. 2.50 lbs.
Compression/Stuff Sack Weight 2.0 oz. 1.6 oz. 2.4 oz. 1.6 oz. 1.2 oz.
Hydrophobic Down Yes No Yes No N/A
Manufacturer Temp Rating 20 F 30 F 30 F 30 F 30 F
EN Temp Rating (Lower Limit) 20 F Not rated 29 F 30 F 29 F
Fill Weight 14.1 oz. 13 oz. 10.2 oz. 15 oz. 21.1 oz.
Compression or Stuff Sack Included Waterproof Stuff Stuff Compression Stuff Stuff
Shell material 20D Recycled Pertex Quantum Extremelite (12D) Ripstop nylon (20D) 20D Nylon Ripstop Polyester w/ DWR
DWR Treatment Yes No Yes Yes No
Liner material 20D Recycled Nylon n/a 30D Nylon Taffeta w/ DWR 30D Plain weave nylon Polyester
Neck Baffle Yes No Yes No No
Small Organization Pocket Yes No Yes Yes Yes
Zipper 3/4-length / Left Side Full-length / Side 3/4-length / Side 3/4-length / Left Side 3/4-Length / Left Side
Shoulder Girth 63.8 in. 64 in. 62 in. 62 in. 62 in.
Hip Girth 52.8 in. Not stated 54 in. 53 in. 56 in.
Foot Girth 40.9 in. 39 in. 59 in. Not stated Not stated

Our Analysis and Test Results

The Rab Neutrino 400 is a great all-around sleeping bag with recycled materials, an effective draft collar, and good ventilation, but its 800FP down insulation can't quite keep up with the 850FP and 900FP down found on other high-end bags.

Performance Comparison


Rab Neutrino 400 backpacking sleeping bag - the rab neutrino 400 is lightweight and warm making it ideal for...
The Rab Neutrino 400 is lightweight and warm making it ideal for cold sleepers or backpackers that like to get out in the shoulder seasons.
Credit: Jack Cramer

Warmth


The 400 in the name Rab Neutrino 400 signifies the 400 grams of down insulation it contains. In English units that translates to 14.1 ounces and that quantity is actually a little less than average for a bag with this warmth. That might be because the down is lofty 800 fill power. This insulation, combined with a cozy neck baffle to seal in heat, earns the Neutrino a 20F temperature rating. In our tests, the rating seemed to be accurate.

Rab Neutrino 400 backpacking sleeping bag - this bag incorporates a neck baffle that wraps 360-degrees around...
This bag incorporates a neck baffle that wraps 360-degrees around the collar of the bag to seal heat it down to its 20F rating.
Credit: Jack Cramer

Weight


The Neutrino 400 features a streamlined mummy design with a strong taper from the head to the foot of the bag to minimize materials and overall weight. On our scale, a size long weighed in at 1.91 lbs. That's nearly the same weight as our favorite 20F bags from Western Mountaineering and Feathered Friends. However, we believe those bags provide more warmth than their 20F temperature ratings while the Neutrino merely meets it. Therefore, we think the Neutrino has a great, but not best-in-class, warmth-to-weight ratio.

Comfort


All of our testers were fans of the supple 20-denier recycled nylon used to line this bag. They also appreciated that the outer shell incorporates recycled Pertex Quantum. We were less pleased, however, with the taper at the foot of the bag. This taper is stronger than that seen on many other sleeping bags and several testers complained that the foot box felt uncomfortably constrictive. In contrast, the upper body dimensions seemed rather spacious for a lightweight model.

Rab Neutrino 400 backpacking sleeping bag - the hood and neck baffle drawcords are made of firmer elastic that...
The hood and neck baffle drawcords are made of firmer elastic that can be a little annoying to your face and neck.
Credit: Jack Cramer

Packed Size


We were able to squeeze the Rab Neutrino 400 down to an impressively svelte 8.9 liters of volume. That's near the top of the field for bags that offer the same amount of warmth. Keep in mind that we achieved those results with a third-party compression sack. The Neutrino comes with its own sack but it's a roll-top waterproof design. The waterproofness may be desirable to some but the roll-top closure makes it fairly hard to pack it down fully.

Rab Neutrino 400 backpacking sleeping bag - the rab neutrino 400 comes with a roll-top waterproof stuff sack...
The Rab Neutrino 400 comes with a roll-top waterproof stuff sack. This seemed to be waterproof initially but we worry the thin material might not stay fully waterproof for very long.
Credit: Jack Cramer

Versatility


This bag's lightweight design and 20F temperature rating limit its versatility to some extent. The lightweight design sacrifices the bag's spaciousness and we worry it's probably too constrictive for extended trips. At the same time, the 20F temperature rating and minimal venting possibilities make this bag too warm for many summer backpacking applications. Instead, it's a bag that's best suited for ounce counters or mountaineers looking to shave a little weight for colder trips during the shoulder seasons or at high elevation.

Rab Neutrino 400 backpacking sleeping bag - there is a y-shaped zipper slide to prevent the zipper from...
There is a Y-shaped zipper slide to prevent the zipper from snagging. It seemed to be moderately effective for this purpose.
Credit: Jack Cramer

Features & Design


Our favorite feature on the Rab Neutrino 400 is the neck baffle. This baffle wraps 360 degrees around the collar of the bag to snuggle your neck and shoulders and prevent heat from escaping out of the main body of the bag. There is also a small stash pocket adjacent to the baffle to stow a headlamp. Unfortunately, the stash pocket isn't large enough to store most larger smartphones.

Rab Neutrino 400 backpacking sleeping bag - there is a small accessory pocket near the collar of the bag. it is...
There is a small accessory pocket near the collar of the bag. It is big enough to stash a headlamp or small smartphone.
Credit: Jack Cramer

Value


The critical question for a premium sleeping bag like the Rab Neutrino 400 should not be: is the bag good? This bag is unquestionably good. The critical question instead should be: how does the bag compare to other premium sleeping bags? In this regard, it also does pretty well--it performs better than most similarly priced bags. But compared to the absolute best premium bags from Western Mountaineering and Feathered Friends, the Neutrino is a clear step behind. For this reason, we don't consider it an exceptional value for the price.

Rab Neutrino 400 backpacking sleeping bag - the rab neutrino 400 utilizes 400g of 800fp goose down. that makes...
The Rab Neutrino 400 utilizes 400g of 800FP goose down. That makes it a modest deal for a bag with this amount of high-quality insulation.
Credit: Jack Cramer

Conclusion


With impressive warmth, minimal weight, and recycled materials, what's not to like about the Rab Neutrino 400? On an objective scale, not much. This is an excellent sleeping bag. On a comparative scale, however, this bag reveals a few subtle flaws that include a narrow foot box and limited versatility. If you're going to spend serious money for a premium sleeping bag, you should get the best, and the Neutrino isn't quite there. You should give it serious consideration if you find it on sale, but at full price, we would opt for a best-in-class model from another company.

Jack Cramer

Ad-free. Influence-free. Powered by Testing.

GearLab is founded on the principle of honest, objective, reviews. Our experts test thousands of products each year using thoughtful test plans that bring out key performance differences between competing products. And, to assure complete independence, we buy all the products we test ourselves. No cherry-picked units sent by manufacturers. No sponsored content. No ads. Just real, honest, side-by-side testing and comparison.

Learn More