Bikepacking Sleeping Bags: Sleep Like a Mummy

Alongside a suitable sleeping pad, the sleeping bag is a key part of your sleep system for a bikepacking trip. In this buying guide, we'll show you how the different fill materials differ from one another, how important weight is, what sleeping bag shapes exist, and what makes the right bikepacking sleeping bag for you.

Mummy or blanket-style sleeping bag: which shape suits you?

There are blanket-style (rectangular) and mummy sleeping bags. For outdoor use, the mummy shape has decisive advantages: by leaving only a small viewing gap when needed and fully enclosing the head, the mummy construction cuts down on the otherwise very high heat loss through the head. For 3-season or winter use, and as an all-rounder, there's really no way around a mummy sleeping bag. For summer gram-counters chasing the lightest possible setup, a blanket-style bag can be a highly specialised alternative.

Comfort, limit, extreme: how to correctly read the temperature ratings

Outdoor sleeping bags are usually given three temperature values (according to EN 13537): comfort temperature, limit temperature, and extreme temperature. To determine these values, standardized manikins – built in size, weight, and body fat to represent an average Central European man or woman – are first warmed to body temperature. Lying in the sleeping bag on a sleeping pad, the heat loss is then measured in a standardized climate chamber. Why all this effort? Because how cold someone feels is entirely subjective and depends, besides the person themselves, on external factors such as fatigue, nutrition, humidity, wind chill, and much more. The measuring method is meant to approximate an average sense of temperature as closely as possible.

Here's how to read the resulting values:

Which temperature ratings matter for a sleeping bag?

For your sleeping bag buying decision, only the comfort temperature and the limit value really matter. If you tend to feel the cold, always go by the comfort value! If you're less sensitive to cold, look towards the limit temperature! The extreme value only matters for expeditions and alpinism, where the sleeping bag can literally determine survival until rescuers possibly arrive. Otherwise, it's only good for bar talk.

You typically reach the comfort temperature with the hood closed and the draft collar done up. Sleeping bags with a comfort range around or above roughly 10 °C are also called summer sleeping bags; those with a comfort range between 0 and 10 °C are called 3-season sleeping bags; and thick bags with comfort temperatures well into the negatives are winter sleeping bags.

Our tip for choosing the right temperature range for your sleeping bag:

Assess your sleeping bag use realistically, and don't buy a bag that's far too thick and warm out of a misplaced sense of security! That costs you not only money, packed size, and weight, but also sleep comfort, through heavy sweating. It's best to base your choice on your typical use and factor in a bit of a buffer! If it does get a little colder than expected, there are ways to "tune" your sleeping bag a bit further. More on that in the chapter:

Handling and care for your sleeping bag

With proper handling, a sleeping bag is an extremely robust piece of gear that will stay with you for a long time. There are a few things you should definitely keep in mind, though. With a few extra tricks, you can also squeeze a few extra degrees out of its comfort range.

Our sleeping bag tips for on the road and at home:

• Ideally sleep in dry (long) base layers and socks inside the sleeping bag. When it gets cold, even thin gloves and a hat can't hurt. This "boosts" the temperature range and also means you won't have to wash your sleeping bag as often.
• In very cold temperatures, also pull a balaclava or a neck gaiter over your mouth and nose. This stops you from burrowing completely inside the sleeping bag, which would let your damp breath get into the down.
• Sleeping bag liners (preferably made of silk, merino wool, or microfiber) don't just protect the sleeping bag from dirt – they can also significantly extend its temperature range.
• Air out your sleeping bag for as long as possible in the morning after getting up, ideally in the sun or a light breeze, before packing it away. This is especially important for down sleeping bags.
• Stuff the sleeping bag into its stuff sack foot end first! This is not only less stressful, quicker, and more space-efficient than rolling, but is also especially good for down sleeping bags, since you're not forcing the down inside the baffles in one particular direction.

• Air out your sleeping bag thoroughly after your trip before putting it away!
• Don't store your sleeping bag compressed for long periods! High-quality (down) sleeping bags are often supplied with a breathable storage sack. Alternatively, you can hang your sleeping bag in the closet like a long coat.
• Sleeping bags can be washed. Synthetic-fill sleeping bags are somewhat easier to handle here: use a fabric-softener-free liquid detergent or a special detergent for insulation fibers – not a down wash – at max. 40 °C, and then spin your sleeping bag on the lowest setting! Note: give the sleeping bag plenty of room. A large 10-kilogram drum is ideal. The sleeping bag can then be dried on a line, on a drying rack, or in a tumble dryer at low temperature.
• Wash down sleeping bags as little as possible but as much as necessary. They always need a special down wash and a maximum of 40 °C. The same rules apply here: large drum, plenty of room, gentle spin cycle. Afterwards, let the down sleeping bag air-dry, spread out on a drying rack for a few hours, before putting it in the dryer with a few tennis balls at max. 40 °C until it's completely dry. The tennis balls matter because they break up clumps of down and help it loft back up.

FAQ: Bikepacking sleeping bags

Which sleeping bag is suitable for bikepacking?

In bikepacking, three things matter in particular: low weight, small packed size, and a temperature range that matches your travel dates. In practice, that usually means a mummy sleeping bag with down or high-quality synthetic fill. As a rule of thumb for 3-season trips in Central Europe, a comfort temperature of around 0 to 5 °C works well; in high summer, a light summer sleeping bag is enough. It's also important to choose a high-quality, well-matched sleeping pad.

What does the comfort temperature of a sleeping bag mean?

Sleeping bags are rated with three values under the EN ISO 23537 standard. The comfort temperature is the temperature at which an average woman is just not yet cold and can sleep well. If you tend to feel the cold, you should definitely stick to the comfort range. If you're not very cold-sensitive, you can go by the limit temperature. The extreme temperature is a pure survival figure and isn't relevant for planning a bikepacking trip.

What temperature calls for which sleeping bag?

On warm midsummer nights, a light summer sleeping bag with a comfort temperature of 15 degrees is usually enough. For cooler summer nights or classic 3-season use from spring to autumn, you should choose a sleeping bag with a comfort range of roughly 0 to 7 °C; for cold nights or higher altitudes, go below 0 °C. It's better to plan in a bit of a buffer, since being cold is usually more unpleasant than a few extra grams of luggage. A liner and the right sleeping pad add extra warmth on top.

Down or synthetic: which is better for bikepacking?

Both materials have their place. Down offers the best warmth-to-weight ratio and the smallest packed size, is long-lasting, but more expensive and loses its warmth when wet. Down sleeping bags need to be kept as dry as possible and should never be stored compressed long-term. Synthetic fiber is cheaper, still keeps you warm when damp, dries quickly, and is easier to care for. Synthetic-fill sleeping bags, however, are heavier and bulkier. For ambitious, weight-conscious bikepacking, down is usually the first choice; if you're often out in wet conditions or keeping an eye on your budget, synthetic fiber serves you well.

Is synthetic fiber (synthetic down) as good as real down?

Modern synthetic fills ("synthetic down") have become significantly better and come closer to real down. However, for the same warmth rating, they don't quite match the low weight and small packed size of a down sleeping bag. The big advantage of synthetic down is that it still insulates even when it gets damp, and it also dries faster. For consistently dry conditions and minimal luggage, real down remains ahead. Synthetic fiber scores points on moisture resistance, easy care, and price.

Mummy or blanket-style sleeping bag: what suits bikepacking?

For bikepacking, a mummy sleeping bag is almost always the better choice: it's cut close to the body, so it insulates more efficiently, and packs down lighter and smaller. A blanket-style bag offers more freedom of movement and can often be fully unzipped, but is heavier and bulkier. It's better suited to car camping. If you don't like the snugness of a mummy bag, a quilt (blanket-like, open underneath) is an ultralight middle ground.

How small and light should a bikepacking sleeping bag be?

As a rough guide: a good 3-season down sleeping bag often weighs under one kilogram and can be compressed to about the size of a small melon; ultralight models come in even smaller. Synthetic fiber weighs a bit more for the same warmth and has a larger packed size. What matters most is that it fits into your bikepacking bag.

What can I do if I'm cold in my sleeping bag?

The most common reason is cold coming from below: without a well-insulating sleeping pad (high R-value), even the best sleeping bag won't help much. More tips: eat something before going to sleep (your body needs fuel to generate heat), wear a hat, put on dry clothing, use a liner, and don't climb into the sleeping bag with a cold body – warming up briefly beforehand helps. A hot water bottle (e.g. your water bottle filled with warm water) also works wonders.

Why should you wear little or thin clothing in a sleeping bag?

The common advice that "you sleep warmest naked" is a myth when stated that broadly. What's true is this: thick clothing inside a sleeping bag compresses the fill from the inside and weakens exactly the insulating layer of air that keeps you warm. Ideal is dry (!) thin base layers (e.g. merino), together with dry socks and a hat – sweaty clothing will cool you down.

How do I properly care for and store my sleeping bag?

On tour, you should air out your sleeping bag well in the morning so the moisture from your body can escape. At home, never store your sleeping bag permanently in its compression sack – instead, keep it loosely in a large storage bag. Wash your sleeping bag as often as necessary and as rarely as possible. For a down sleeping bag, you need a special down detergent, and after some air-drying it should be tumble dried with a few tennis balls so the down lofts back up. Synthetic fiber should likewise be gently washed with a special synthetic-fiber detergent and then dried. This keeps your sleeping bag warm for years to come.

Is hydrophobic (water-repellent) down worth it for bikepacking?

Hydrophobically treated down absorbs moisture more slowly and keeps its
fill power for longer. That's a real advantage on bike trips with rain or dampness in the tent. However, it doesn't eliminate down's biggest weakness: once it gets truly wet, even hydrophobic down barely insulates anymore. In consistently damp conditions, synthetic fiber remains the better choice. For most 3-season trips, hydrophobic down is a good compromise between low weight and somewhat better moisture resistance.