ULA CDT Ultralight Backpack Review

ULA CDT Backpack ReviewThe 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.

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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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, a front 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 drawstring top closure or a roll top.

The main compartment has a long extension collar to accommodate extra gear storage. It closes with a drawstring, 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 seeping in through the pack seams in rain or if you place it on the wet ground. All packs, even so-called “waterproof” Dyneema DCF backpacks, suffer from this because sewing shoulder straps and hip belts make 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 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 Nylon fabric for extra durability, including reinforced pocket bottoms. The top of each pocket has an elastic cord that 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 helps 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 is 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 an excellent value if you want a very lightweight pack that combines functionality and durability.

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


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

    • Increasing discomfort as the pack collapses under the load. But no.

      • I’ve put up to 25 lbs in it with no problem. I usually put my tent right down the middle of the pack and then put sleeping pad on one side and sleeping bag on the other. This creates a nice structure inside the pack and then it can handle heavier loads without a problem. This pack is by far the most comfortable pack I have, whether I’m carrying 12 lbs or 25 lbs.

  2. 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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