Outdoor Vitals CS40 Ultra Backpack Review
Outdoor Vitals has recently come on my radar within the last year or so. I’ve been thoroughly impressed with everything I’ve tried, so I was excited to test out the Outdoor Vitals CS40 Ultra Backpack. This backpack was insanely light, crazy durable and quite comfortable.
Ultralight Frame

You know what sounds awesome? An ultralight backpack that functions and feels like a standard back country pack. This is exactly what Outdoor Vitals has done with their legendary 2 oz frame. In order to save weight, many ultralight backpacks are frameless. This may feel fine for the first few miles but after hours of packing it quickly becomes apparent the weight just doesn’t sit right and your back pays the price.
The CS40 Ultra Backpack uses ultralight carbon fiber frame stays to distribute the load. This results in an ultralight pack with the functionality and weight distribution of a ordinary, heavier pack. Don’t sacrifice, get the best of both worlds with the CS40 Ultra Backpack.
Ultraweave Material

The CS40 Ultra Backpack is constructed from Ultraweave fabric which is as light DCF (a comparable ultralight fabric) yet 6 times more abrasion resistant and twice as strong. The fabric is also fully waterproof. I could not be more excited about the durability of this fabric. We all know packs take a beating on the trail and having a durable pack is essential. The waterproof fabric is also great for early morning condensation and light rain.
Note: while the fabric is fully waterproof the seams are not weather sealed.
Design

The overall design of this pack is wonderful. For me, 40L is the perfect amount of space for anything from day trips to multiday overnights. I have, however, been forced to master the art of light packing and understand that others may prefer more room. The main compartment is spacious, and the roll-top closure keeps gear secure and dry, though a few more internal organization options could be nice. The water bottle holders and outside mesh pocket is great.
Comfort-wise, the shoulder straps and hip belts are nicely padded and breathable, which is rare for a pack with this weight.
Specs
- Weight – Size M, 27 oz
- Capacity – Size M, main compartment 40 L
- Frame – Yes, carbon fiber frame
- Close Type – Roll top
Pros & Cons
Pros:
Ultralight and Durable: The CS40 Ultra Backpack boasts an impressive combination of lightness and durability thanks to the Ultraweave fabric and ultralight carbon fiber frame. This allows for comfortable carrying even on long hikes without sacrificing strength.
Comfortable Design: The pack features well-padded and breathable shoulder straps and hip belt, providing a comfortable fit despite its lightweight construction. This is a significant advantage compared to many other ultralight backpacks.
Versatile Capacity: The 40L capacity is perfect for a wide range of activities, from day trips to multi-day overnights.
Cons:
Limited Internal Organization: While the main compartment is spacious, the pack lacks extensive internal organization options. This may be a drawback for users who prefer more compartmentalized packing.
Unsealed Seams: Although the fabric is waterproof, the seams are not weather sealed, meaning the pack may not be fully waterproof in heavy rain.
Verdict

Overall, the CS40 Ultra ($329.97) is a fantastic backpack constructed from top of the line materials with true backpacking enthusiasts in mind. I doubt you can find a lighter more functional backpack on the market.