This post may contain affiliate links.

KS-Ultralight Gear KS-50 Backpack Review

KS-Ultralight Gear KS50 Backpack Review

The KS-Ultralight Gear KS-50 is an ultralight backpack that’s good for thru-hiking and multi-day backpacking trips with a max recommended (comfortable) load of 20 lbs (9kg). When ordering a KS-50 you have the option to customize it in many different ways in order to tailor it for your needs and preferences. I examine the fabrics and features I chose on my custom KS-50 below, but KS-Ultralight Gear has a near-infinite range of options available, so you can customize the KS-50 to your exact needs.

Specs at a Glance

  • Volume: 48L
  •  Weight
    • Backpack including hip belt and aluminum stays- 18 oz
    • Additional 2.2 oz for optional 1L hip belt pockets
    • Additional 2.3 oz for Gossamer Gear Thinlight 1/8″ closed cell foam pad.
  • Materials:
    • 200D Nylon/Spectra
    • 330D Cordura
    • 3D mesh on shoulder straps and cell foam pad pockets.
  • Sizing:
    • Torso length: 53 cm (fits 18″-21″)
    • Hip belt length: 95 cm (fits 32-38″)
The large durable front pocket provides lots of convenient storage.
The large durable front pocket provides lots of convenient storage.

Fabric Choices

KS-Ultralight Gear offers backpacks in Nylon 200D Spectra, Dyneema DCF, VX07, X21RC, EPX200, and Ecopak Ultragrid 200. They use 330D Cordura by default for shoulder straps, side pockets, and hip belts. Although KS-Ultralight Gear offers their packs in waterproof fabrics like X-pac and Ecopak, none of their packs are seam-sealed. A pack liner is recommended.

In my case, I ordered a KS-50 backpack primarily made of Nylon 200D Spectra, including the main body, side pockets, and hip belt. The bottom of my pack is constructed of 330D Cordura. Outfitted with KS-Ultralight Gear’s optional hip belt pockets and a 1/8″ Gossamer Gear Thinlight pad, my KS-50 weighs 22.5 oz and provides enough flexibility to meet the demands of my weekend backpacking trips.

Backpack Frame and Suspension

The KS-50 is available with external aluminum stays and load lifters.
The KS-50 is available with external aluminum stays and load lifters.

I ordered my KS-50 with the external frame option, which is comprised of two aluminum stays secured by small pockets and loops along the sides of the pack. These aluminum stays help to better transfer loads to the hips and help keep the load more rigid. The stays can be removed but the weight penalty for the extra support is only a few ounces.

I included line-loc load lifters on my KS-50, although KS-Ultralight Gear also offers them using webbing. While they do bring the pack’s load closer to my back, they are oddly shallow in angle in comparison to the load lifters on other packs I’ve worn.

The hip belt is sewn to the base of the pack and only lightly padded. KS-Ultralight Gear claims that their packs’ comfort limit is 20 lbs (9kg), and I’ve found that I can comfortably wear my KS-50 all day without any discomfort at that weight or less. Carrying more is a lot less comfortable.

Sitpad pad pocket w: Gossamer Gear Thinlight Foam Pad
I ordered a sit pad pocket for use with Gossamer Gear Thinlight Foam Pad

Adding a Thermarest Z-pad or other closed-cell foam pad like Gossamer Gear’s Thinlight 1/8″ pad to the back of the KS-50 increases the pack’s rigidity and support for carrying loads. I would say that using one is almost an absolute necessity for comfort’s sake, as a closed-cell foam pad also prevents objects in your pack, like a small bear canister, from poking you in the back. Even then, you shouldn’t expect the sort of luxury comfort you’ll get from a more traditional ventilated backpack from Osprey or Gregory. After a few miles of hiking with the KS-50, I often find that my back is sopping wet.

Backpack Storage and Organization

Closed Storage

The KS-50 is a simple pack with a large cylindrical main compartment.
The KS-50 is a simple pack with a large cylindrical main compartment.

The KS-50 is actually a 48-liter pack. There are 36 liters of space in the main compartment, which includes the extension collar, 8 liters in the front pocket, and 2 liters in each side pocket. The main compartment is a single, large cylinder. Customers can order their backpacks with a draw cord or a roll-top closure.

KS-Ultralight claims that the KS-50 and KS-60 can carry a BV 500 bear canister vertically inside the main compartment. While I can fit my similarly sized Bearikade Blazer into the KS-50 in this way, there’s not enough room for all of my other gear unless I secure it to the outside of the pack. I’d get more volume if that’s a scenario you’re likely to experience.

I recommend getting the 1L hip belt pockets because they are so high utility.
I recommend getting the 1L hip belt pockets because they are so high utility.

KS-Ultralight Gear also offers one-liter hip belt pockets for their packs, which are attached by elastic straps and hooks. I originally decided to order my KS-50 without hip belt pockets only to realize how much I missed having them. They are just so darn convenient and well worth the few extra ounces they add to my backpack’s overall weight.

Open Storage

The KS-50 has an open 8-liter front pocket, which I had made with low-stretch Nylon 420D on my KS-50. It provides enough room for my toiletries, snacks, sunscreen kit, a two-liter Vecto bladder, and a Platypus Quickdraw filter.

The side pockets can hold 2 x 1L smartBottles
The side pockets can hold 2 x 1L tall bottles

The KS-50 also offers side pockets with ample room for two 1 liter bottles each, or one 2 liter bottle. But retrieving water bottles from these side pockets while wearing the backpack is frustratingly impossible. However, KS-Ultralight Gear recently enlarged the side pockets which may help alleviate this problem.

I ordered a pad pocket to hold a Gossamer Gear Thinlight as a sit pad, but if I had to do it over again, I would have ordered my KS-50 with simple bungee cords to the pad in place. I find putting the foam pad back into its 3D mesh pockets is unnecessarily time-consuming and inefficient.

I opted for a roll top closure and a simple top strap.
I opted for a roll-top closure and a simple top strap.

External Attachments and Compression

While you can order a V or Y strap for carrying a bear canister on top of your pack, I opted for the KS-Ultralight Gear’s standard 13 mm strap which is secured by a hook and D-ring. While I find the D-ring and hook a bit fiddly at times, it’s a simple, light design that works well overall.

Side compression is provided by paracord strung along the sides of the pack and is a simple way to secure items like water bottles, tent poles, trekking poles, and the like.

My KS-50 has daisy chain webbing sewn along the shoulder straps, allowing for accessory pockets or electronics to be hung from them.

Backpacking with the KS-50 in the White Mountains
Backpacking with the KS-50


The KS-50 Backpack is well made and will meet the needs of solo backpackers who can keep their total pack weight under 20 lbs (9kg). If you can keep your total pack weight including consumables) that low and you want a backpack tailored to your specifications, then the KS-50 or KS-Ultralight Gear’s other backpacks are well worth considering. In addition, see Philip’s review of the KS Ultralight Gear Alpisack Backpack from a few years ago, which is a 56L alpine backpack suitable for winter use.

About the author

Vincent Palmieri has been backpacking since 2009. He completed his New Hampshire 48 in the summer of 2022 on Mt. Isolation and has backpacked extensively in the White Mountains in all four seasons. For the past thirteen years, he and his wife, Deborah, have hiked and backpacked all over North America, including sections of the Colorado Trail, the John Muir Trail, the PCT, the Wind River Range, the Cascades, and the Canadian Rockies. They completed the Tour du Mount Blanc in 2017 and the Hundred Mile Wilderness in 2022, and they have plans to complete the AT in Maine in the near future. Vincent enjoys spending his free time researching gear.


  1. I owe a very similar spec of the KS50 which I have used extensively. It was my main pack for the California section of the PCT in 2019. When I went back in 2022 to hike the Washington and Oregon sections I switched to a Z-packs Nero. So I have experience using this minimalist frame pack and a frameless pack under similar conditions with similar loads.
    I was disappointed to discover, as you mention, that above 20 lbs, the comfort level of the KS drops off FAST. I would even saw that it does no better at supporting heavier loads than the Nero, which has wider shoulder straps. Due to this fact, I would say if you are buying this pack as a bridge between a heavier framed pack and a frameless one, as I was, just get a good frameless one with wide straps or a harness like Nashville Packs offers. You’ll save some weight and complexity and be able to carry the same amount

    As for the water bottle pockets, I have always been able to reach mine with ease. But I’ve never had a problem doing this on any pack, I guess I’m just flexible. I 100% agree, just spec the bungee cord over the 3-D mesh pad pockets. They are heavier and harder to use than bungees.

  2. Couple of things:

    Those load lifters are pretty low angle, but the biggest problem with them is that they’re sewn to the pack bag not a frame component, so you’re really just pulling on fabric, which has a lot of give when you tighten them. That’s often pointless. In fact, KS-UL says they’re only good when the pack is stuffed full. Putting load lifters on a frameless backpack is just cosmetic IMHO.

    I had a pack once (the original Zpacks Blast 32 circa 2009) that used similar external framestays, only they were carbon fiber. They were pretty worthless. I can’t imagine they add much load transfer to your pack either, given yours has a soft minimalist hipbelt.

    • Yes, Phil, you nailed it exactly. The main problem is that the hip belt is so floppy. The stays do a decent job of transferring the load to the hip belt, but the belt itself just folds and digs into your waist. My pack was spec’ed with very narrow webbing on the adjustable part of the belt, so those straps just end up digging into your belly.

      • I will say that I have not had trouble with my belt digging into my hips or crumpling under weight, even at the pack’s max load limit (about 26 lbs). Although, I ordered my pack with the optional 38 mm belt, and so that probably helps. Even so, and as you mention in your post, it is my experience that the pack is not comfortable over 20 lbs.

      • I love my KS50 and find it very comfortable. I have bought other packs over the years but always went back to the KS50. My largest bear cans fit in no worries and I put the padding on the inside. I already do pack UL so being minimally over 20 is fine. SHR approved. I’ve never packed a lot of weight and liked it… So I don’t. I generally hike all day and don’t hang around in camp though. I can reach my water bottles better with my KS than any other pack I have tried. I ordered the KS Omega pack last year and find it equally sound and comfortable. This year my teen son and I had a blast hiking all day in the Eastern Sierra with these packs and any issues we had weren’t pack related. I’m a fan, really good pack to me. I don’t like his website though.

Leave a Reply

Your email address will not be published. Required fields are marked *

Solve *