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ULA CDT Ultralight Backpack Review

The ULA CDT is a frameless ultralight backpack ideal for ultralight backpacking, day hikes, and traveling
The ULA CDT is a frameless ultralight backpack design for minimalist backpacking with base loads of 10-12 pounds.

ULA CDT Backpack



The ULA CDT is a frameless ultralight backpack good for thru-hiking or weekend backpacking trips. It has plenty of storage capacity and is durable enough for challenging trips.

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The ULA CDT is a frameless backpack designed for ultralight backpacking, day hiking, and travel with a manufacturer maximum recommended load of 18 pounds or less. Weighing 19 to 24 ounces(with optional pockets), it’s a streamlined backpack with limited closed storage (36 liters in the main bag+extension collar/54 liters total). While the CDT is not the lightest frameless backpack available today, it’s made with durable fabrics, has large external pockets, and has a number of customization options (women’s-specific shoulder straps, roll-top closure, color, fabric choice) that make it a function-friendly pack to use and personalize for your needs….at a very reasonable price.

Specs at a Glance

  • Total Volume: 3370 cu in /about 54 liters (36 liters in the main bag+extension collar)
  • Weight: 19-24 oz (includes 5 oz optional accessories)
  • Rec’d Max Load: 18 lbs or less
  • Rec’d Base Weight: 10-12 lbs or less
  • Fabric: 210d Robic standard, or 500d Cordura available
  • Torso Lengths: 15-18″, 18-21″, 21-24″, 24″+
  • Hip Belt Sizing: <30″, 30-36″, 36″+
  • Gender: Men’s and Women’s-specific shoulder straps available.
  • For complete specs, visit Ultralight Equipment’s CDT Product Page

Main Compartment and Storage Capacity

The ULA CDT an ultralight style backpack with a large main compartment, rear stretch mesh pocket, roomy side water bottles pockets, with zippered pockets on the hip belt.

The ULA CDT has a stretch mesh rear pocket and large side water bottle pockets. It's available with a draw string top closure or a roll top
The ULA CDT has a stretch mesh rear pocket and large side water bottle pockets. It’s available with a draw string top closure or a roll top.

The main compartment has a long extension collar to accommodate extra gear storage. It closes with draw string, with a piece of top webbing that loops over the top, although a roll top closure is also available on request. That would be my preference, because I think roll tops provide better rain protection and top compression.

Several optional interior pockets come with the pack for storing an internal hydration reservoir (there are two hydration ports on the sides) or personal effects in the main compartment, but can be non-destructively removed with the plastic clips that hold them in place. When using the pack, I recommend that you line it with a white plastic trash compactor bag to protect the contents from wetness seaping in through the pack seams in rain or if you place it on the wet ground. All packs, even so-called “waterproof” cuben fiber backpacks,suffer from this because sewing shoulder straps and hip belts makes holes in the pack’s fabrics, which is I why I recommend lining all backpack interiors with large plastic bags.

The CDT’s side water bottle pockets are solid, not mesh, to protect them from abrasion and tearing. They’re large enough to fit a 1 liter Nalgene or soda bottle bottle with room to spare; it’s also easy to pull out a bottle while walking and replace it without stopping to take off the pack. Both water bottle pockets have drains at their base and are covered with solid 210d robic fabric for extra durability, including reinforced pocket bottoms. The top of each pocket has an elastic cord than can be cinched closed and secured with a cord lock to keep items from shifting or dropping out. The elastic cord is handy when storing longer items that are also lashed to the sides of the pack with a compression strap, like a fishing rod or trekking umbrella.

The CDT has deep water bottle pockets with an angled opening that makes it easy to pull out and replace bottles in the pockets while walking.
The CDT has deep water bottle pockets with an angled opening that makes it easy to pull out and replace bottles in the pockets while walking.

The front of each side pocket has a small hole you can stick your hand into although that’s not the intention; it’s part of the shoulder strap suspension system which terminates at the base of each pocket. While this attachment point helps pull the pack closer to your back, small items can fall out of the side water bottle pockets and they shouldn’t be used for that type of storage.

Like many ultralight style packs, the CDT has a long rear mesh pocket that’s ideal for storing wet gear or layers you want fast access to during the day without having to open up the pack’s main compartment. I typically store my rain gear, water filter, and an empty wet reservoir in the mesh pocket when I hike to keep them away from my dry clothing inside the main compartment. The stretch mesh has a very tight weave and good durability for on-trail use, but I wouldn’t recommend taking the CDT on rugged bushwhacking trips if you want to keep the mesh intact.

The ULA CDT has a simpler hip belt than offered on the companies larger backpacks that are designed to carry more weight.
The ULA CDT has a simpler hip belt than offered on the company’s larger backpacks which are designed to carry more weight.

Finally, there are two zippered pockets on the exterior of the hip belt, large enough to store a point and shoot camera, snacks, Aqua Mira bottles, bug dope, and such. The fronts of both pockets are hard faced to prevent tearing with heavy-duty zippers for durability. If you’re familiar with the wide hip belt that ULA uses on their Catalyst, Circuit, and Ohm 2.0 backpacks, this hip belt is narrower and the pockets are smaller as befits a pack that carries lighter max loads. It’s also sewn directly to the back of the backpack instead of being replaceable.

External Attachment and Compression System

While the CDT has one tier of side compression straps located above the side water bottle pockets, it’s difficult to attach much bulky or heavy gear on the outside, because it is a frameless pack designed for base loads of 10-12 pounds or less (18 pounds total, including water, food, and fuel).

The CDT also conforms more to the shape of its contents than most backpacks with frames and the extra reinforcing fabric to help those frames stay in place, so it takes a little practice to pack comfortably. There two main approaches to this: one is to tightly pack all your gear loose or mostly loose inside the backpack (inside a plastic liner.) Alternatively, you can line the pack with a foam pad, like a Therm-a-Rest Ridgerest, to stiffen up the sides of the pack so it doesn’t collapse into an uncomfortable or unbalanced shape. When using a pad like this you roll it up like a cylinder and drop your gear in the middle.

The side compression straps are handy to lash lightweight items to the sides of the pack
The side compression straps are handy to lash lightweight items to the sides of the pack.

If you pack your gear loose in the CDT and crank down on the compression straps, the sidewalls of the pack take on an hourglass shape because it has so little internal structure. Instead, I use the compression straps primarily for lashing long and very lightweight items like an umbrella or fishing rod to the sides of the pack, and carefully pack my gear to balance and shape the load for the main compartment so that it doesn’t bulge too much. When packing with a cylindrical foam pad, there’s little need to use the compression straps because the foam pad will keep your load centered in the pack and prevent it from shifting.

Backpack Frame and Suspension System

The ULA CDT is a frameless backpack, so proportionately more weight will be placed on your shoulders than a conventional backpack with a rigid frame. Despite this, the CDT is quite comfortable to carry within its stated load carrying limits, because it has wide shoulder straps and wide hip belt side wings that are sewn directly to the back of the pack. The latter also help bring the load in line with your hips and back so that the pack feels like an extension of your back and body. While the CDT does have a removable foam back panel behind the shoulder straps, it’s really designed to prevent contents from poking you in the back instead of providing much torso rigidity and load to hip transfer since it’s not connected to the hip belt in any way inside the pack.

The back of the CDT is padded with a thin, removable foam pad.
The back of the CDT is padded with a thin, removable foam pad.The hip belt also sewn directly onto the backpack unlike ULA’s other backpacks where it’s removable.


The ULA CDT is a frameless ultralight backpack that’s designed for carrying 10-12 pound base loads with a maximum of 18 pounds, including food, fuel, and water. Weighing 19 to 24 ounces (including removable accessory pockets), it has a maximum capacity of 54 liters (36 liters of closed storage) making it ideal for shorter backpacking trips where you have very lightweight but “puffy” gear that you can pack loose or rolled up in a foam pad inside the main compartment. The CDT also makes an excellent day pack if you prefer an ultralight style backpack layout and is also good for travel since it’s frameless, easy to get through security, and stuff in overhead airplane bins. While the CDT is not the lightest frameless backpack available, it is easy to use without giving up on many features commonly found on larger backpacks with frames, like side water bottle pockets, a rear stretch mesh pocket, and hard sided hip belt pockets. While I wouldn’t recommend the CDT for off-trail bushwhacking (because of the rear mesh pocket), it is built with durable fabrics and holds up quite well for heavy-duty on-trail  hiking. Priced at $145, I also consider it a excellent value if you want a very lightweight pack that combines functionality and durability.

Disclosure: ULA loaned the author a backpack for this review. Updated 2018.

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  1. Thanks for another helpful review. I am going to be changing to a lower volume UL pack soon, and am torn between this and the current model Gossamer Gear Kumo. I know you reviewed the older Kumo a while back, but have you had occasion to test the new one? I am very curious to know how comfortable the CDT and Kumo carry their loads when put against each other, and also if the CDT has greater durability/longevity enough to justify the weight difference (along with being more voluminous).

    • Glad you asked that. The Kumo really hasn’t changed that much in the latest iteration. I actually prefer the CDT (although it’s close) because it has a better top closure, better hip belt, and is made with much more durable materials. The top flap closure on Gossamer Gear packs (not the new floating lids) has always been a little fiddly to open and close, whereas the top closure on the CDT is a very straightforward drawstring or optional roll top, which is what I would recommend. The CDT has a much more substantial hip belt and the fabric is way way tougher. I believe that ULA is willing to replace the rear mesh pocket with solid fabric for a small customization fee (something they can do because they manufacture their packs in the USA), something that’d make this pack even more durable and qualify it for off-trail use. I’ve been thinking about buying one for myself for just this purpose. I used a Kumo for many years, but recently donated the several versions of it I had in my gear closet to Good Will because I’d fallen out of love with it. It is slightly easier to pack than the CDT because it has a more rectangular main compartment and holds its shape better, than the CDT which has more of a circular shape when packed. But I prefer having a pack like the CDT that’s more like a bigger backpack, just streamlined, than a pack that more like a daypack/rucksack, which is how I’d characterize the Kumo. This is my nuanced take on the question. Hope it helps. It really boils down to personal preferences. They’re actually both fine packs with lots of fans.

      • One other thing…also take a look at the Ohm 2.0. It’s ULA’s next larger pack and more flexible than the CDT, especially in terms of sizing and fit. at 32 ounces it is substantially heavier, but it is a really sweet pack.

      • Thank you very for the feedback and insight. I’ll definitely take that into consideration!

  2. ” I believe that ULA is willing to replace the rear mesh pocket with solid fabric for a small customization fee (something they can do because they manufacture their packs in the USA), something that’d make this pack even more durable and qualify it for off-trail use. ”

    That is exactly what I had done to my ULA CDT. Costs $25 with S&H IIRC. For off-trail hiking and scrambling in canyon country, it was a wise investment. It service cactus schwacking in Arizona. :)

    I, too, used to use the Kumo…two different versions in fact. But I find the larger size, durability, and ease of use makes the CDT a better pack for my needs I noticed that the newer versions of the Kumo have weight creep. If you strip down the CDT (easily done), the weight difference is small to non-existent between the two packs.

    As a bonus, the CDT has made a great ski tour pack for winter day use. I can load up my winter gear and clothing for the day and because the pack is so durable, I am not worried about tree skiing.

    The Kumo is a good pack; I just like the CDT better for me.

  3. 10-12lb base weight – 18lbs total – does these figures include the weight of the pack (19-24oz), or just the weight of what’s in the pack?

  4. To Philip and Mags, took your recommendation and went with the CDT. After using it on a couple of “breaking in” hikes–I couldn’t be happier. Thanks for the advice, gentlemen.

  5. the sizing on these cottage vendor packs have always been tricky for me to imagine the size/volume, as compared to the larger vendors at the box stores.
    specifically, 52L CDT seems large enough, but that includes all the open storage…
    how does this compare to my aging Osprey Talon 44, in terms of capacity, as I know you have reviewed in the past.
    Thanks, love the site.

    • You really couldn’t pick two more different backpacks to compare. The CDT is larger but it depends on how you pack. I’d try both to decide which you like better. You might well try the CDT and never ever bother with the Talon…

      • Thank you fine Sir. I think I will have to try the CDT, been using the Talon for years, but looking to the CDT to save one pound from my base load… Love the site

  6. Are there risks to packing more than the recommended 18lb?

  7. Of the roll top and cinch top, which do you prefer?

    • Roll tops are almost always better than cinches. A cinch might save a few grams but at the expense of functionality. A roll top gives you another dimension of load compression that a cinch doesn’t give you, not to mention it’s a lot tougher for stuff–leaves, dirt, water, bugs–to get into a closed roll top than a cinch top.

      I recently got a CDT (with the front mesh replaced with robic) and it’s a really great pack. Haven’t used it a ton yet but it feels perfectly fine with a 9-ish pound base with plus a couple days food and a few liters of water (I always carry a lot of water. It’s how I pack my fears. Desert fears).

      Takes some work to get it packed right but it just takes a little thought and it carries real nicely. It’s a little heavier than some other frameless packs, but it also comes at a great price and, I don’t know how this will play out long term because I’ve only had mine a few weeks, but it feels tough on par with heavier-fabricked mainstream stuff.

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