I’ve owned a Western Mountaineering UltraLite 20 degree sleeping bag for 4 years and I reckon I’ve backpacked over 1,000 miles with it. With an MRSP of $370, the UltraLite is one of the most expensive items I’ve ever purchased for backpacking, but it has proven its value repeatedly and with proper care, I expect it will last another 10 years.
If you’re not familiar with Western Mountaineering, they are considered one of the top sleeping bag manufacturers, with a worldwide reputation for making very lightweight and compressible bags using 850+ fill power goose down. Weighing just 1 pound 13 ounces, the UltraLite is one of the lightest weight 20 degree sleeping bags available and easily compresses into a 8 liter waterproof stuff sack when packed.
Fitwise, the UltraLite is one of the slimmest Western Mountaineering’s bags available with a shoulder/hip/foot girth of 59″/51″/38″. The narrow cut helps keep the weight of the bag down and makes it easier to warm up because there isn’t much free space inside it. The lightest weight sleeping bags have high fill power down and narrow dimensions like this.
The outer cover on the UltraLite is breathable lightweight nylon with a DWR coating. The DWR coating has broken down over the years and I need to reapply it the next time I give the sleeping bag a wash in a laundromat. Occasionally, the foot box will be a bit damp when I wake up, but I can’t tell if this is do to exterior condensation (I often sleep in a UL bivy sack) or interior perspiration by my feet. Regardless, it dries within a few minutes in the morning before I stuff the bag into its stuff sack.
In addition to the narrow fit, the UltraLite has a down collar the runs around the upper chest to prevent heat from escaping when you move around at night. The bag has a full zipper which is useful for venting in warmer weather as well as a down filled draft tube running the length of the bag to prevent side drafts. In addition, the baffles are continuous, making it possible to move down from the bottom of the bag to the top if more warmth is required or from top to the bottom where it will be compressed and not retain heat, in warmer weather.
Temperature-wise, I’ve had the UltraLite down into the low twenties without any issues and I feel that it’s temperature rating is true.
If there was one thing I could change about the UltraLite, it would be it’s weight and warmth. I often find it a little bit too warm in New England except in early spring or autumn. I bought this bag before I understood how to augment the warm of a sleeping bag by wearing additional cold weather clothing and I’d probably go for a Western Mountaineering 32 degree SummerLite, if I had a chance to go back 4 years in time.
However, I’m not ready to buy a SummerLite if I can avoid it and I still haven’t fully exploited the ability to move down away from the top of the UltraLite to its bottom using the continuous baffles. With summer on the horizon, I have plenty of time to see how these changes affect the UltraLight’s warm weather profile and temperature range.
Disclosure: The author owns this product and purchased it using their own funds.
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