When searching for light outdoor gear, it has proven itself a good idea to look at what long distance hikers choose. Simply, because those who walk miles with all their belongings strapped to their backs, do usually know best. So when we exchanged our heavy, four pannier road-touring setup last year in Arizona for a lighter bikepacking rig, we did exactly that. At the time, we were carrying two sleeping bags each to withstand the extreme cold, traveling in early spring through Alaska. But with our desire to become lighter and eventually being able to ride more trails and venture deeper into the mountains, we knew that we needed a more compact, lighter and versatile solution.

On our search we stumbled across Katabatic Gear. The company was founded by Aaron Martray from Colorado in 2008. As he thru-hiked the Colorado Trail, he started to think about what could be improved about one of the most important pieces of gear that he carried: the sleeping bag. A year later he started his own company. Since then he has specialized in making lightweight quilt style bags and has field tested his own products on many extensive hikes ranging from Alaska to Tierra del Fuego.

The basic idea of a quilt style sleeping bag is to eliminate the insulation that is at the bottom of a conventional sleeping bag. The reason behind this is that with a conventional sleeping bag, the insulation is crushed and does lack the loft it needs to trap warm air effectively. By using a quilt you’re saving weight and volume. Obviously when using a quilt the insulation and quality of your sleeping pad directly affects your sleeping system.

For our bikepacking journey from the US down to the Andes of South America we have been using the Katabatic Flex15 in combination with Exped down-filled sleeping pads. The first thing we noticed when we received and unpacked the sleeping bags was that the materials used felt strong and sturdy. Many other lightweight sleeping bag materials we have looked at in comparison seemed more flimsy and fragile.

Neither of us had any experience using a quilt bag before and, needless to say, we were a little bit skeptical. However, we liked the versatility the Flex 15 from Katabatic Gear offered and decided to give it a try. As we planned to zigg-zagg across the Americas, being lightweight wasn’t the only major criteria we looked at. We also needed a sleeping system which could provide enough warmth to sleep high up in the Andes mountains in South America, but could also accommodate more mild and hot climates, which we would encounter in Mexico and in the lowlands.

The Flex 15 from Katabatic Gear can be opened up completely and used as a blanket, which is perfect for warmer nights. The additional zippered foot box features a versatile system that offers numerous options for ventilation or complete warmth. A zipper, a drawstring, a snap and a down-filled draft blocker allows you to decide whether to lock out the cold or allow a little fresh air in.

Katabatic Gear lets your choose between two different goose down fillings. It is worth mentioning that all the down they use is responsibly sourced through Allied Feather and Down, and in addition they offer their customer access to the Track My Down program.

For our Flex 15, we chosen 850 Fill Power Water-Resistant Goose Down, with an overfill of 3oz. So when we set out cycling in Peru over 4000m, with temperatures dropping way below zero at night, we really could get a feel of how the Flex15 performed. As in general, temperature ratings come more as a suggestion and there are many variables to consider, as comfort levels and the personal cold tolerance can vary. That said, both of us felt warm and toasty in our bags, even when the temperatures dropped below -10C at night, when we crossed the Salar de Uyuni in Bolivia.

Katabatic Gear uses a simple and easy to handle attachment system for their quilts, which allows you to fix your quilt on top of your sleeping mat instead of under. That said, don’t worry you won’t need a specific sleeping mat, this system works with any mat. It is simple, it uses two cords and two clips, with which you can secure your bag with. Once you clip the bag into the two cords which are strung around your mat, it stays where you want it to be, snug around you. In addition the Flex 15 features an overstuffed down collar. We can honestly say that we are really impressed by the performance of the Flex15, we felt absolutely comfortable setting out with it into the cold. For the coldest nights we would actually close the quilt using the zipper plus the straps and then connect the quilt using the cords to the mattress to prevent it from movement in the night. This works pretty good and is the warmest configuration of the Flex 15.

We also love the 850 Fill Power Water-Resistant Goose Down. Depending on humidity, at times, we would wake up in the morning to slightly damp sleeping bags. However, this is not a problem as it literally only takes a few minutes in the sun to dry out completely. Definitely a very valuable feature when you, like us, are highly dependent on reliable and good functioning gear.

The Verdict
Having used the Flex 15 almost every night for the past year, camping in various conditions ranging from hot to very cold, we are really happy with its performance. This quilt style bag offers many ventilation options without sacrificing comfort and warmth. The material used is durable and absolutely suitable for long and extensive trips. With its high quality down, light weight, versatility and small packing size the Flex 15 performed really well as a multi season sleeping system, illuminating the need of shipping several season sleeping bags on a long-term trip like ours.

Katabatic Gear | Flex 15 | Regular Size | Weight 31.4oz (including the 3oz overfill) | 850 fp | Temperature Rating -10C \ 15F. Price varies on size and down fill, but you can find out more information on their website… https://katabaticgear.com/shop/flex-15-sleeping-bag/


Franzi and Jona (Tales On Tyres) have been traveling by way of foot and bike since 2012 after quitting their jobs in Germany. Since then traveling has been their life goal. They have traversed numerous countries, and are currently zig zagging their way down the Americas. Franzi and Jona are supported by Bombtrack CyclesSinewave Cycles and Katabatic Gear. Make sure you spend some time flipping though their Lookbook, its a beautiful compilation of photos and words from their journey traveling down the Baja divide. 



  1. Great write up! What tent is that in the last few photos?

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