Gear Review: Klymit Inertia X-Frame

Is your sleeping pad from the Stone Age? Try upgrading to this Jetsons-worthy mattress.

Although I typically avoid leading with the punch line, in this case I’ll make an exception; I was utterly astounded by the effectiveness of this sleeping pad. Two broken clavicles, one broken shoulder, and three knee surgeries have turned me into a rather discerning backcountry sleeper, and the X-Frame’s Spartan construct concerned me immensely. Fortunately, my worries were unwarranted. The 1.5” thick pad has cushion in all of the right places thanks to ‘body-mapping’ technology, which essentially means there’ s padding provided at your body’s primary pressure points when you’re horizontal: your head, shoulders, hips, calves, and feet. These points are connected by thin tubes (see photo 1, above), leaving empty space where the padding is unnecessary. This architecture serves two purposes: a) less material means it can easily pack down to a size that fits in the palm of your hand (see photo 2) while weighing a hair over 9 ounces, and b) your sleeping bag can loft into the vacant space and retain more of your body’s heat. As a bonus, it’s also easy to inflate (it took me four or five good breaths) and quick to deflate, too. Klymit includes a handheld pump to inflate to a PSI beyond what you can do with your own lungs, but I never needed it. Durability wasn’t a concern either; a combination of 30 denier ripstop on the top and 75 denier ripstop on the bottom translated to a product that felt a lot tougher than it’s diminutive size initially conveyed.

My first two nights of testing occurred in Yosemite National Park while tenting on a slab of granite with patches of snow, and both nights dipped below freezing. Amazingly, I was just as warm and comfortable in my 20 degree bag as any other night of backcountry sleeping, and the cushion was so effective that I could even sleep on my side (my personal preference). Additional nights along Olympic National Park’s legendary coastline (see BACKPACKER's recommended overnight itinerary) confirmed what I already suspected: this pad’s comfort to weight ratio is unsurpassed by anything I’ve slept on. However, you do have to be careful to ensure your body stays lined up properly with the body mapping technology; I woke up a couple of times to find that I had worked my hips into empty pockets between padding. The pad is skinny enough to fit inside of a mummy bag, which will help alleviate the problem, but I still preferred keeping the pad on the outside so I could more easily roll around inside my bag.

Bottom Line: The X-Frame is an excellent choice for the fast and light, three-season crowd who are still looking for a little bit of cushion at the end of their day.