The Rab Guide to Sleeping Bags
mountaingroupSLEEPING BAG SPECIALISTS SINCE 1981
The Rab Guide to Sleeping Bags
To this day, we hand-fill our down-insulated sleeping bags at our factory in Derbyshire, UK. This allows us to know with certainty that when our bags reach our customers, they have never been compressed or stored in a way that could be detrimental to the down interior. Our lightweight and packable sleeping bag options are ideal for alpine climbers, mountaineering trips, or general winter conditions due to their compact size and excellent warmth-to-weight ratio. 3-season and 4-season sleeping bags are available with synthetic and hydrophobic down fill options.
Their values remain valid; our products are cut, sewn, and finished in Derbyshire. Our attention to the smallest detail and the simplest innovation allows us to manufacture sleeping bags that last a lifetime.
The Different Ranges
In 1973, while heading out on an expedition to Patagonia, Rab Carrington found himself stranded in Buenos Aires. A dock strike in the UK had delayed the arrival of his gear, and he found himself in desperate need of money.
Running out of money and ideas, Rab turned to his friend, Héctor Vieytes, who had just secured a small contract sewing sleeping bags for the Argentine army. After much persuasion, Héctor hired Rab and began teaching him the skills that would come to redefine the future of technical sleeping bags.
To this day, Rab makes the world's best sleeping bags, and whether you're camping in the Lake District or planning an attempt on an 8000m peak, your choice of sleeping bag can mean the difference between a restful night's sleep and shivering until dawn.
Our Materials
Rab sleeping bags are used worldwide from the highest alpine peaks and polar expeditions to the hills and valleys of our native UK. For this reason, we go to great lengths to use the best materials available on the market.
Responsible Down Standard
The Responsible Down Standard (RDS) is an independent global standard by which companies voluntarily choose to certify their down products, even if there is no legislation requiring it.
The RDS has been developed and revised over three years with contributions from animal welfare groups, industry experts, brands, and retailers. This standard identifies best practices for animal welfare and excludes those that harm it.
Nikwax Hydrophobic Down
The safe, high-performance, PFC-free water-resistant down fill for outdoor clothing and gear. Keeps users warmer and drier in a wider range of conditions.
Pertex Quantum
Pertex® Quantum is a lightweight, soft fabric with a tight weave structure. These properties make it an ideal complement for down clothing, as it allows for complete insulation. It is also highly wind-resistant, so warm air inside the jacket stays there even in strong winds. Pertex® Quantum also has a very durable water repellent (DWR) treatment.
Pertex Quantum Pro
Pertex® Quantum Pro uses a water-resistant coating to provide increased weather resistance. This makes it ideal for jackets that will be used in the mountains year-round, especially when hydrophobic down is also used.
Fill Power
The quality of a down product's fill is called fill power, or loft, and is measured in cubic inches (cuin). To determine the fill power, an ounce of down is placed in a graduated cylinder where the volume in cubic inches that the down occupies when expanded is measured.
The volume that an ounce of feathers can reach can vary between 550 and 900 cubic inches (in some cases, even better quality can be achieved), depending on the animal, the type of plumage, and the selection method used. The higher the fill power, the higher its quality. On the other hand, and contrary to popular belief, fill power or fill quality alone does not determine the thermal capacity of a product, as we must also consider the amount of fill. For example, a -10° C sleeping bag provides the same warmth whether it is filled with 850 or 600 fill down. The difference is that the 600 fill power bag needs more down to reach that temperature range, so it will be heavier and less compressible than an 850 fill power bag.
Temperature Ratings
It's important to understand that a sleeping bag doesn't warm you up; its function is to retain the heat your body generates, preventing you from getting cold. Our ratings describe how well a sleeping bag retains heat when the air outside the bag is at a certain temperature.
Because all our bodies are different, what one person needs for a good night's sleep is not necessarily the same as the next. This means it is difficult to quantify exactly how warm a sleeping bag is, and as such, any rating should be treated as a guide. At Rab, we use the European standard EN13537 to rate most of our sleeping bags.
EN13537 is a European standard designed to regulate sleeping bag temperature ratings across the industry. The test assumes a 'standard male' is 25 years old, 1.73 m tall, and 73 kg, while a 'standard female' is 25 years old, 1.60 m tall, and 60 kg. The EN13537 rating is determined using a thermal mannequin to accurately record a series of measurements from the 'Upper Limit', the temperature at which a person can sleep without perspiring, to the 'Extreme Limit', which determines the minimum temperature at which a person can survive.
For our EN13537 tested sleeping bags, we list the three lowest temperature ratings: comfort, limit, and extreme, as well as our own Rab sleep limit.
Comfort Rating
This rating expresses the optimal temperature you will experience when wrapped inside your sleeping bag. You should use the comfort rating as the basis for your purchase.
Lower Limit Rating
The 'lower limit' measurement is the temperature at which the test's 'standard male' can remain asleep for eight hours without waking up due to heat loss.
Extreme Rating
The extreme rating expresses the absolute limit of a sleeping bag. It should be used to guide a bag's performance in an emergency situation rather than as a recommended use case. It refers to the temperature at which a 'standard female' can remain for six hours without risk of death from hypothermia.
Rab Sleep Limit
We have created the 'Rab Sleep Limit' to complement the results of the EN13537 standard. It is not an 'emergency' metric in the same way as the 'Extreme Rating', but what we believe is the usable limit of the bag.
The Rab sleep limit is what we believe to be the sensible limit of the bag based on past experience and feedback from our athletes.
Insulation
Down's main weakness is its susceptibility to moisture, which can cause clusters to collapse and lose their insulating properties. Here at Rab, we protect our down with a Nikwax Hydrophobic Down™ treatment. Hydrophobic down will absorb much less moisture and dry much faster than other downs. However, it still cannot perform as well as synthetic alternatives in humid environments.
Down is a huge product worldwide now and can be obtained in a wide variety of stated fill powers and qualities. At Rab®, all our down is European sourced and is sourced and processed by our long-standing partner in Germany. Long-term relationships build trust, and we know this is the only way to ensure the quality and performance synonymous with Rab® sleeping bags. We use only the highest quality down in our sleeping bags, all of which is fully traceable and accredited under the Responsible Down Standard to ensure animal welfare. Because down is a natural material, it can vary in each grade, so each and every batch we use is independently tested to ensure our demanding standards.
Fill Weight
Fill weight is the primary factor in the warmth of a down sleeping bag. It refers to the total amount of down used in the construction of the bag and is generally measured in grams. Generally speaking, the more down there is within a sleeping bag, the warmer it will be.
Fill Power
If you were to take 1 gram of fully lofted down and measure its volume, the result would represent the down’s fill power. The greater the volume, the more air that can be trapped and the better the down will insulate.
Goose down typically has the highest fill power, normally ranging from 600 to 850, whereas duck down usually has a fill power that ranges from 500 to 700.
The range of down that we use allows us to fine tune our sleeping bags to meet the different demands of our customers, both in terms of budget and the intended use of the bag.
Weight & Packability
Warmth is the main concern when buying a sleeping bag, but it is also important to consider both weight and pack size.
It is possible for two sleeping bags to have a similar temperature rating but very different weights and pack sizes. For some people, warmth is the only concern. If you are getting to your campsite by car, or you are setting up a base camp, then a bulky, heavier bag might be fine, but if you are carrying your kit up into the mountains, then every gram matters.
For example, if you compare two of our bags, the Neutrino Endurance 400 and the Summit 600, both have a similar temperature rating (-6°C and -6.5°C respectively), yet the Neutrino Endurance is 285g lighter and packs down to 18 x 27cm rather than the Summit’s 22 x 39cm. Both bags will keep you warm, but if you are travelling light or you have limited space in your pack, then the Neutrino Endurance is clearly the better choice. The trade-off is that the 800 fill power used in the construction of the Neutrino Endurance 400 makes it considerably more expensive.
All our sleeping bags come with a stuffsack, some of which are waterproof. If you are storing your down sleeping bag for an extended period, we do not recommend using a stuffsack, as this can affect the natural loft of the down. To prevent this, we also provide you with a much larger cotton storage bag for when your bag is not in use.
The range of down that we use allows us to fine tune our sleeping bags to meet the different demands of our customers, both in terms of budget and the intended use of the bag.
Hand-Filled in Derbyshire
The bags we make can make the difference between life and death, which is why to this day we hand-fill all of our down sleeping bags in our factory in Derbyshire, UK.
It means we can make sure that every baffle is filled as required, and that the down inside has never been compressed or stored in a way that can affect performance.
We simply wouldn’t trust anyone else to do it.
How are the bags filled?
Bags are filled with a small diameter pipe and a compressed air system, which blows the feathers into each chamber.
How is Quality maintained?
Before bags are filled, an empty shell from each batch is weighed to ensure that they are within tolerance. Precision scales are then used to measure the down into each chamber and once complete the finished bag is weighed again. To avoid being rejected, the total bag weight must be under 10% and cannot be under the anticipated weight. Our scales are accurate to 0.5g and are routinely recalibrated using 1000g, 100g, 10g and 1g weights.
Technical Synthetic Insulation
Although Rab is best known for down sleeping bags, there are occasions when synthetic insulated bags are appropriate. Unlike non-hydrophobic down, synthetic insulation is better at dealing with moisture and will keep you warm even when wet. It is also easier to clean and care for and is generally cheaper than down, but crucially it has a lower warmth to weight ratio.
In our Ignition range we use Pyrotec™, a synthetic insulation developed exclusively in Rab to provide the best possible balance of softness, compressibility and warmth versus weight. Pyrotec™ is created by blending microfibres and hollow core fibres into sheets; the microfibres provide softness, flexibility and heat retention whilst the hollow core fibres add loft and spring to the material.
Although generally heavier and less efficient at retaining warmth than their down equivalents, the performance of our Pyrotec™ bags is much less inhibited in damp environments. They are also much easier to care for.
Construction
As you explore our range of sleeping bags, you will note the differences in their features, their shape and the fabrics that we use to construct them.
Below, we highlight the key features to consider.
Baffles and Differential Cut
When we use the term baffle it is in reference to a ‘baffle mesh’ – the fabric walls that divide a box wall sleeping bag into chambers. The height of a baffle is determined by the measurement between the sleeping bag’s lining and outer shell. Down with a higher fill power or higher fill weight will require more space, but too much baffle height causes the shell to sag, adds weight and allows for cold spots to occur. Conversely too little baffle height can restrict the down’s ability to loft, resulting in an underperforming bag.
Differential cut is the difference in size between the inner and outer shell of the sleeping bag. When looking at a particular series of sleeping bags, the inner shells will generally be the same size but the outer shell may need to be increased to accommodate a greater down weight or higher fill power down as you progress up the range.
Shape and Fit
Regardless of fill power or fill weight, if a sleeping bag is too large you will lose heat. We offer standard, women’s specific and extra-long sized sleeping bags to accommodate different body sizes. Our Expedition series bags are sized slightly larger to accommodate the bulky down clothing required in extreme environments.
Shape is another important consideration, most Rab bags use either a ‘Mummy’ or ‘Tapered Mummy’ shape. Mummy shaped bags are wide at the top to fit the shoulders and narrow slightly towards the feet to prevent dead spots and draughts.
Tapered bags, such as our Neutrino range, are a closer fit and are narrower in the leg than Mummy shaped sleeping bags. This means they are lighter and more thermally efficient, but they can also feel a little constricting.
Outer Fabrics
We use a variety of fabrics throughout our range. Some situations require the lightest possible fabric, whilst for other users, durability or water resistance may be more important.
Uncoated outers, such as Pertex® Microlight, are breathable, lightweight and packable but do not offer as much protection against moisture as a fabric such as Pertex® Endurance. For example, our Neutrino Endurance range of bags have better moisture resistance and are more durable than the Neutrino range, but at a cost of 85g and less breathability.
Inner Lining
All of our sleeping bags use lightweight, breathable nylon fabrics such as Pertex® Quantum for their inner linings. These are generally stronger than polyester equivalents. Some lower end bags may use fabric linings but these add weight and increase the packed size of the bag.
Our range of sleeping bag liners are there for when you would like an extra level of comfort. They can also mean your bag will require less frequent washing and can add warmth.
Hood
To reduce the amount of heat lost from your head, all of our bags have shaped hoods and adjustable neck baffles. The addition of a drawcord allows you to pull the hood tight against your face to retain as much heat as possible.
Zips
A zip is often an insulating weak point in a sleeping bag. We minimise this by using draught tubes – a tube of insulation that runs behind the full length of the zip.
The Rab Range of Sleeping Bags, the best bags in the world
It has been over 30 years since the first Rab sleeping bag was hand cut, stitched and filled in a small terraced house in Sheffield. Having spent years in the mountains, Rab Carrington’s original designs were inspired by his experience. Making products for climbers by climbers, function and performance was the basis of his designs.
Ascent Range
Alpine Pro Range
Neutrino Range
Neutrino Pro Range
Mythic Range
Expedition Range
