The OV CS40 is a weight-weenie's dream at just 27 ounces while still hauling an impressive 53L total capacity. I'm not kidding—this thing's made from Challenge UltraWeave that's 6x more abrasion-resistant than competitors. It's waterproof, has smart storage options, and supports up to 35 pounds comfortably. At $330 (less with a membership that I highly suggest), it's actually cheaper than comparable ultralight packs. The carbon fiber frame stays make all the difference when you're 20 miles in.
Revolution in a rucksack. That's what Outdoor Vitals has created with their CS40 backpack. I've tested dozens of packs over the years, but this one's different. Weighing just 27 ounces, it's practically weightless on your back. But don't let that fool you. This thing's tough.
The secret? Challenge UltraWeave 200 fabric. It's waterproof. It's 6x more abrasion-resistant than comparable materials. And get this—it's twice as strong as 500D Cordura. That's insane for something this light. They made it white to reflect heat, which sounds impractical but works brilliantly on trail.
Outdoor Vitals
Challenge UltraWeave 200 fabric defies physics—ultralight yet bombproof, with that brilliant white finish keeping you cooler on scorching trails.
Storage is thoughtfully designed. The main compartment holds 41L (M/L size), with external pockets bringing total capacity to 53L. There's a massive 6L front mesh pocket that I stuff with wet gear as needed, plus two side pockets for water bottles. The hip belt pockets? Perfect for snacks and my electronics needed on the go.
Comfort matters most when you're logging serious miles. The CS40 comes in three torso lengths with interchangeable hip belts. The padded shoulder straps didn't dig in, even after 20-mile days. The load lifters actually do something useful, unlike some packs that just pretend. Carbon fiber frame stays provide structure without weight.
I pushed this pack to its limits. The 35-pound recommended maximum load? I tested it. The weight transferred beautifully to my hips. The contoured bottom kept everything snug against my back. No bouncing, no shifting.
Let's talk features. Hydration compatible? Check. Trekking pole loops? Yep. Four lashing loops on the bottom for a sleeping pad? Got 'em. The three-point compression system kept smaller loads stable. The carbon fiber stays extend the full length of the back panel, creating an effective suspension system that performs like a traditional full-framed pack.
Outdoor Vitals
It's not perfect. The seams aren't sealed, so it's not completely waterproof. And at $368, your wallet will feel it. But compared to competitors like Zpacks Arc Haul, you're getting comparable quality. The CS40 is significantly more affordable at $330 retail, or even less with an Outdoor Vitals membership.
Who's this for? Hardcore backpackers, thru-hikers, even weekend warriors who count ounces. Anyone who wants a pack that won't fall apart after one season.
Bottom line: The OV CS40 is fundamentally ultralight magic. It carries like a dream, holds everything you need, and will probably outlast your hiking boots. Sometimes revolution comes with a roll-top closure.
