Note: At my request, Big Agnes provided me with the sleeping bag and sleeping pad for the test.
I have known Big Agnes for many years and I am an avowed fan of this American outdoor brand. So far, however, I have only focussed on their tents and have been using a Copper Spur UV UL 1 Bikepack for several years, which I also used when racing in Kyrgyzstan.
But the Americans have also been making sleeping bags and sleeping mats for some time now. And they have an integrated sleeping system in which the sleeping bag and sleeping pad fit together perfectly. This is well known, at least in the USA – but I hadn’t been aware of it until now.
And when I was given the opportunity to test both, I chose the Fly Creek UL 25° sleeping bag and the Zoom UL Insulated mat.
Before I go into more detail about the sleeping bag and the sleeping pad, I have to say that during my research and final product selection for the test, I was surprised at how committed Big Agnes obviously is to sustainability.
Yes, I know, you should always scrutinise that. However, the products I have looked at tend to suggest that it is meant seriously: the outer material and lining of the Fly Creek UL sleeping bag are made from so-called NetPlus 10D nylon ripstop, which is made from recycled fishing nets. And the fabric is water-repellent impregnated without ‘intentionally added PFAS’.
Info: PFAS stands for per- and polyfluorinated alkyl substances – a large group of man-made chemicals that are used in many everyday products because they are extremely water-, grease- and dirt-repellent.
PFAS are problematic because they…
- are extremely persistent: PFAS hardly degrade in the environment – they are therefore also called ‘eternity chemicals’.
- pose health risks: Some PFAS are suspected of being carcinogenic, affecting the immune system or damaging fertility.
- contribute to environmental pollution: PFAS end up in drinking water, soil and the food chain – often from industrial waste water or by leaching from products.
PFAS-free products are therefore always preferable.
But Big Agnes also focusses on sustainability when it comes to down: it is impregnated with a water-repellent finish to maintain its insulation value even when wet. To achieve this, they use an 850 Downtek PFC-free filling with water-repellent, bluesign-tested chemistry without intentionally added PFAS.
850 means the fill power of the down. 850 cuin (cubic inches) means: 1 ounce (approx. 28 g) of this down fills a volume of 850 cubic inches. And the higher the number, the warmer the down is for the same weight. This down is RDS-certified, i.e. it does not come from live plucking, the animals are kept in a species-appropriate manner and there is complete traceability along the supply chain.
Downtek is a water-repellent treatment for down. It prevents the down from flattening out in damp conditions and losing its insulating effect. This treatment is PFC-free, which means that the impregnation does not use so-called perfluorinated chemicals – i.e. without PFAS.
In the test: Big Agnes Fly Creek UL 25°
One special feature of the Fly Creek UL 25° is immediately noticeable: the zip. This only runs across the top half and is centred. Unlike other sleeping bags, where the zip is often sewn in at the side. In practice, this is convenient as you simply slip in and then close the zip while lying on your back. I also have short zips on my other sleeping bags. I quite like this, but if you want to use the sleeping bag as a blanket or have it open at the feet, you need to consider a sleeping bag with a full-length zip.
The Fly Creek has a large hood that can also be adjusted separately. There is a cord on the inside at the edge of the hood at the level of the collar on the right. In practice, I have not yet had to tighten it, as the hood fits very well and does not slip away.
I am 1.84m tall and opted for the Regular size. According to Big Agnes, this is only suitable for people up to 1.83m, but in practice there is still plenty of room. I fit very well in the Fly Creek with an inner sleeping bag and still have enough space in the upper body area. Especially in cold temperatures, I sleep with my arms inside, so I still need some space. This works quite well in the Fly Creek. The foot area is a little narrower than in my other sleeping bags, but so far ok.
According to Big Agnes, the Fly Creek has the following dimensions:
- Shoulder circumference: 152cm
- Hip circumference: 137cm long
- Foot circumference: 91cm
But let’s get to the most important thing: the sleeping bag is designed for a comfort temperature of 2 degrees and a limit of -4 degrees. This makes it an ideal companion for me in late autumn, winter and spring, when the temperatures at night are around or below freezing.
Lately I’ve been having problems with the warmth of my Cumulus X-Lite 400, which I also had with me in Kyrgyzstan. Somehow the insulation is no longer right, or I’ve become more sensitive. With the Big Agnes, however, I was surprised at how well the insulation worked and how warm it was. And that at temperatures below 0 degrees at night.
This is probably due to the 850-fill-power down, which delivers a good performance. And that with a total weight of the Fly Creek of 730g (reweighed – 722g according to the manufacturer). And 480g of down is used.
This is probably also due to the construction: the upper part of the sleeping bag is quilted. Big Agnes calls this ‘Signature Diamond quilt-through construction’.
In concrete terms, ‘quilt-through’ means that the top and bottom layers of fabric of the sleeping bag are sewn directly together, creating chambers for the down. ‘Diamond’ refers to the diamond pattern (like small diamonds) in which the seams are arranged.
This construction ensures that the down filling remains evenly distributed, does not slip and the sleeping bag retains a compact, stable shape.
Perhaps I need to have my down filling distribution checked again by Cumulus, because with the X-Lite I can see against the light that the down is no longer evenly distributed and is therefore less warm. This is particularly noticeable in the lower area and on the back.
Big Agnes therefore uses a so-called ‘baffled construction’ on the bottom and sides. This means that partitions (baffles) are sewn into the inside of the sleeping bag between the outer and inner shell to keep the down filling in separate chambers. In contrast to the simpler ‘quilt-through’ technique (which is used in the upper area), the baffled construction offers better insulation, no cold bridges at the seams and a stable down distribution. However, this construction method is somewhat heavier and more complex.
My Cumulus X-Lite 400 weighs 600g, the Big Agnes Fly Creek 730g. However, I feel this extra weight of 130g directly in the warmth performance and would prefer it. I have used the Cumulus Panyam 450 on particularly cold trips, which weighs 900g and provides a similar level of warmth to the Big Agnes.
But you mustn’t forget that I’ve been using Cumulus sleeping bags for a very long time and have used them a lot. So I’ll have another look in a year’s time (after the winter) to see how the Big Agnes performs.
The Big Agnes Fly Creek UL 25° is currently priced between 450 and 550 euros. This is the same price level as comparable high-quality sleeping bags. In terms of weight, it is absolutely competitive. And even when stuffed, it takes up no less space than the Cumulus Lite Line or Panyam.
Conclusion Big Agnes Fly Creek UL 25° sleeping bag
This sleeping bag will definitely be with me in the coming autumn/winter/spring, as it offers very good warmth, the hood holds very well and the space inside (mummy-fit) is just right for me.
The packing volume and weight are also fine for me. It fits well in my handlebar roll, together with my sleeping mat, inner sleeping bag, pillow and sleeping clothes.
If you like it lighter and more compact, you should also take a look at the Quilt version of the Fly Creek.
I have seen that Globetrotter has Big Agnes on offer. So if you want to get a direct impression, you can certainly find the Fly Creek in the shop.
In the test: Big Agnes Zoom UL Insulated
No matter how good the sleeping bag is, without a suitable sleeping mat, even the best down will not help if it gets cold from below. This is why the so-called R-value (thermal resistance) plays an important role in insulating mats. This indicates how well the mat insulates heat – i.e. how effectively it keeps the cold off the ground and retains your body heat.
The higher the R-value, the warmer the sleeping pad. You can find a rough guide here:
R-value Range of use:
- 1-2 Summer, warm nights
- 2-3 Spring/autumn, mild temperatures
- 3-4 3 seasons (also cool nights)
- 4-5 Cold conditions, light frost possible
- 5+ Winter, snow, expeditions
Interestingly, Therm-a-Rest, Sea to Summit and Big Agnes test their mats according to the same criteria – the values are therefore easily comparable.
I have been using Therm-a-Rest mats for many years. Currently the Neoair X-Lite for winter, as it has an R-value of 4.5. And the Uberlite in summer, with an R-value of 2.3.
In addition to the R-value, the weight and pack size are the most important factors for me. The Neoair weighs in at 350g and the Uberlite at 250g.
With the Zoom UL, Big Agnes now also offers sleeping mats and focusses more on comfort. The Zoom UL is available in three sizes. I opted for the 25×72 mat. This means that the mat is 63.5 cm wide and 183 cm long. And that with a thickness of 9cm. This gives the Zoom UL an R-value of 4.3, which makes it a very good all-season mat (at least in this country). However, if the ground is frozen, Big Agnes recommends placing additional insulation under the mat.
The width of almost 64cm is remarkable, as this mat fills at least my 1-person tents (Copper Spur and Fly Creek). But it also increases comfort and I have to say that I sleep very well on it.
For comparison: the Neoair and the Uberlite are both 51cm wide. This means they also weigh less, although the Big Agnes, with a weight of 490g (reweighed – 482g according to the manufacturer), has nothing to hide. Sea to Summit, for example, is heavier.
However, the Zoom UL is also available in a width of 51cm. Then the weight is a competitive 397g.
And to follow on from my comments on sustainability at Big Agnes: the sleeping pad is made from so-called ‘post-consumer recycled nylon ripstop’. This means that the material is made from recycled nylon that was originally used by end consumers and then recycled. It comes from used products, e.g. old items of clothing, carpets, fishing nets or industrial waste that have been recycled after use. This distinguishes it from pre-consumer recycling, where only production surpluses or offcuts are used.
Two layers of heat-reflecting film have been installed inside, which you can also hear. The mat is a little louder (crackling), which you should bear in mind if you are sensitive to noise. It is as loud as the Neoair Xlite. I noticed it less in the tent than indoors. I heard it clearly there and it woke me up from time to time. Outdoors, it wasn’t a problem for me.
A pump bag is included in the package, as the Zoom UL is not a self-inflating mat. However, I only tried the pump bag once. I then inflated the mat by mouth. Big Agnes says that the valve has two functions, which should enable quick and easy inflation and micro-adjustments for an individually customisable degree of firmness.
It took me a while to understand the valve: in practice, it’s a fairly large valve hole that lets air in but not out. This makes it easy to inflate the mat. My initial criticism, however, was the deflation. This only worked if I pressed a finger firmly on the valve core to let the air out.
So when I wanted to pack the mat up again and roll it up, I had to press the air out of the mat with my upper body and keep the valve open with my finger. This was particularly annoying when rolling it up.
But I was sure that this couldn’t be the way and that Big Agnes certainly hadn’t designed this valve that way. I then looked for instructions and found what I was looking for in a test video: you have to insert part of the valve cover into the valve. This opens it permanently and ensures that the air can escape.
I tried this and it worked. Once, this valve cap popped out of the valve when I was rolling it up. I just wonder why they have solved it in such a complicated way and not with a ‘normal’ valve like the competition? At least Big Agnes could point out more about how the valve works, or I simply overlooked it.
This is where I think Big Agnes needs to improve. Especially to keep up with Sea to Summit and TAR, who have made their mats very easy to use. Otherwise, this mat is very comfortable and highly recommended.
With a price of approx. 200 euros, the Zoom UL is in the ‘normal’ range of top insulation mats, but should also justify this price in terms of usability (valve).
Conclusion Big Agnes Zoom UL sleeping pad
If you are currently looking for good sleeping pads, you should include the Big Agnes Zoom UL in your comparison. Globetrotter, for example, sells this mat and you can certainly get an impression there.
In terms of price and weight, it can keep up with the top dogs from TAR. As with the sleeping bag, I like the fact that Big Agnes is focussing on sustainability and using appropriate materials.
And I am still impressed by the comfort of the mat. The width of 64cm is really comfortable and helps with regeneration after a long day on the bike. I have also used it in sub-zero temperatures at night and it has also delivered. The compactness of the Zoom UL with its 20×11/2cm is also completely ok. This makes it about the same size as the TAR Neoair Xlite with 22×11 cm.
However, the valve is not yet optimal from my point of view, which is why I have to give it a minus point here.
