It’s easy to understand the advantages of ultralight backpacking. With less on your back you’ll have more fun. You feel more free and closer to nature. Choosing a lightweight sleeping bag is one of the great ways to start lightening your backpack.
A warm, good night’s rest is crucial when you’re backpacking. You don’t want to sacrifice comfort at night for minimal weight savings during the day. If you make the right purchase you can rest better than ever and still trim the weight and bulk of your sleeping bag.
Most backpackers can reduce the weight of their sleeping bag by a couple of pounds because their current bag is overkill. Hikers buy heavier bags just in case they go on winter trips. Since most of their hikes are in the summer, or part way into the spring and fall, they end up sweating in their bags and unzip them as far as possible. Sometimes the bag is so hot it ends up being nothing more than another pad with a warm backpacker on top.
It’s more logical to buy a light bag and add something like a silk liner to extend the bag when necessary. Some people like to use a liner because it’s much easier to clean than the bag. If you plan to use the bag in winter, it can still be doubled with another bag.
High fill power goose down is the best insulation material available. It provides more warmth per ounce than any other material. Down-filled sleeping bags are as much as 35% lighter than synthetic bags. Down sleeping bags are much more compressible, so they take up less room in your pack. Down is also known for its longevity and lasts at least three times longer than synthetics. I know of bags from the 1970s that are still going strong. Factor in the lifespan of a down bag when you make your initial investment.
The fear of a wet bag is the most common concern people give for avoiding down bags. But any bag is uncomfortable when wet. It’s actually fairly difficult to get a down sleeping bag soaked. You’d have to go through a sequence of events (mostly avoidable) to get your bag drenched once it is fully lofted. It’s hard to get down wet because it has natural oils in it. Geese are waterfowl and they’ve been perfecting their down for millions of years. Have the proper equipment to keep your bag dry and increase your skills in camp placement. Always keep your bag in a waterproof stuff sack or pack. Know how to reduce condensation in your tent. Keep a towel handy to wipe tent walls. If you camp under a tarp, you may need a super light bivy to protect your bag. Choose a campsite that can’t become a mini stream running under you if it rains.
High quality down bags are most often made with shell fabrics that have a very tight weave. Durable water repellent finishes are added. As time wears the durable water repellent finishes thin, a new coating can easily be applied. The combination of tight weaves and water repellent finishes is enough to repel normal dew and condensation. Quality shell fabrics are also highly breathable.
The fill power number of the down will give you an idea of the quality of the down. The best down lofts higher per ounce and gives more warmth.
A roomier bag will take longer to heat up and will have more heat loss when air moves in and out of the bag with your movement. Narrower bags are the lightest and most temperature efficient if you don’t mind a snug fit.
Some people need full-length zippers so they can open the bag all the way on warm nights. The lightest bags sometimes have no zippers or partial zippers to reduce weight and increase efficiency. Consider whether you want a left or right zipper. Most hikers want left zip bags because as you’re lying on your back it’s easier to reach across your body to your left side to use the zipper.
For a lightweight summer bag you probably don’t need every feature, such as draft tubes down the side or draft collars at the top. More features equal more weight. Buy only what you need to reduce the cost as well as the weight.
Temperature ratings are an estimate and vary from person to person. Use them as a starting point. Your metabolism is responsible for how comfortable you will be at a given temperature in your bag. Your comfort level can change from day to day not only from outside temperature changes, but from your own energy level, food intake, and whether you’re well hydrated. Ask others and check hiking forums to discover which brands give the most realistic temperature ratings.
When you purchase the right ultralight sleeping bag, you’ll enjoy the weight savings every day and the comfort every night.