Ultralight Adventure Equipment Catalyst Review

Name: Ultralight Adventure Equipment Catalyst
Brand: Ultralight Adventure Equipment

This pack rides the line as an ultralight bag that's still comfortable to carry, has useful features, and boasts impressive durability

When you have less weight on your back you feel lighter, and have an easier time enjoying the experience.

Credit: Elizabeth Paashaus

Price: $320 List

Manufacturer: Ultralight Adventure Equipment

By Adam Paashaus ⋅ Review Editor ⋅ May 16, 2024

OVERALL
SCORE

RANKED
#3 of 12

Comfort - 40% 8.5
Ease of Use - 25% 8.0
Weight-to-Volume Ratio - 20% 10.0
Adjustability - 15% 5.0

View at Ultralight Adventure Equipment

Our Verdict

Since debuting in 2001, ULA (Ultralight Adventure Equipment) has been a prominent force in the long-distance hiking community. ULA describes the Catalyst as a “tried and true workhorse,” and we would have to agree wholeheartedly. This pack weighs considerably less than most of the competition, fitting easily into the weight range of our lineup of ultralight backpacks, yet comfortably carries loads as well or better than many of the fully-featured packs we tested. The features, while simple, are extremely user-friendly and made in a way to reduce excess weight. Anyone who considers themselves a lightweight backpacker, but wants the ability to carry a little more weight from time to time, will love this pack. This may not be the most innovative or high-tech backpack in our test, but ULA sticks with the basics with the useful and comfortable Catalyst. Compare it to top competitors in our backpacking backpacks review.

REASONS TO BUY

Lightweight

Comfortable

Supportive

Functional feature set

REASONS TO AVOID

No lid

Back panel lacks ventilation

Minor Updates for 2025
While the core of this pack remains the same, ULA has made some minor improvements and additions to the Catalyst — and all their packs — including:

New more durable mesh (claimed) for the front pocket

Ice axe / trekking pole loops are now a standard feature

Loops on top and bottom to attach optional Y straps that can be purchased from their website

Compare to Similar Products

(change comparison)

	This Product Ultralight Adventure Equipment Catalyst	Granite Gear Blaze 60	Osprey Atmos 65 AG	REI Co-op Flash 55	Osprey Aether 65
Awards	Best Lightweight Support for Long Distances	Best Overall Backpacking Backpack	Best for Superior Comfort	Best Bang for the Buck	Best for Carrying Heavy Loads
Price	$320 List	$164.97 at Backcountry Compare at 2 sellers	$305.61 at Amazon Compare at 3 sellers	$199 List $199.00 at REI	$266.75 at Amazon Compare at 3 sellers
Overall Score	82	87	83	81	80
Star Rating	1 2 3 4 5	1 2 3 4 5	1 2 3 4 5	1 2 3 4 5	1 2 3 4 5
Bottom Line	This comfortable yet supportive pack has an extremely functional set of features and is one of the lightest in our test	This super-light pack caries loads like a pro and has just about every feature you could ever want	This now classic pack offers incredible ventilation, an awesome set of pockets, and a hug-like suspension	The Flash 55 is a great value, with excellent features and a great weight to volume ratio at an affordable price	This heavier but more comfortable pack provides great support for larger loads
Rating Categories	Ultralight Adventur...	Granite Gear Blaze 60	Osprey Atmos 65 AG	REI Co-op Flash 55	Osprey Aether 65
Comfort (40%)	8.5	9.0	10.0	8.0	9.0
Ease of Use (25%)	8.0	9.0	8.0	8.0	8.0
Weight-to-Volume Ratio (20%)	10.0	8.0	5.5	9.0	5.0
Adjustability (15%)	5.0	8.0	8.0	7.0	9.0
Specifications	Ultralight Adventur...	Granite Gear Blaze 60	Osprey Atmos 65 AG	REI Co-op Flash 55	Osprey Aether 65
Measured Weight	2.8 lb	3.0 lb	4.6 lb	2.8 lb	5.0 lb
Advertised Volume	75 L	60 L	65 L	55 L	65 L
Weight per Liter	0.60 oz/L	0.80 oz/L	1.13 oz/L	0.81 oz/L	1.23 oz/L
Organization Compartments	Front mesh pocket, side water bottle pockets, hip belt pockets	Lid, front mesh pocket, side water bottle pockets, hip belt pockets	Lid, front mesh pocket, side water bottle pockets, hip belt pockets	Lid, front mesh pockets, 2 side pockets per side, hip belt pockets, shoulder strap pocket	Lid, front pocket, side water bottle pockets, hip belt pockets
Access	Top	Top, front	Top, sides, bottom	Top	Top, front, bottom
Hydration Compatible	Yes	Yes	Yes	Yes	Yes
Sleeping Bag Compartment	No	No	Yes	No	Yes
Materials	400 Robic fabric	100D robic nylon w/ DWR coating	Main Body: Recycled 210D honey comb nylon Accent: Recycled 210D high tenacity nylon Bottom: Recycled 500D high tenacity nylon	Main Body: 100D ripstop nylon Bottom: 420D nylon	420HD nylon, DWR treatment
Measured Volume (main compartment)	55 L	58 L	50 L	45 L	45 L

Our Analysis and Test Results

The Catalyst is, far and away, one of the lightest weight packs that can comfortably carry a moderate load. Despite this low weight, it still has enough features to continually remain one of our favorite packs.

ultralight adventure equipment catalyst - the ula catalyst has everything a long-distance hiker wants in a pack. — The ULA Catalyst has everything a long-distance hiker wants in a pack.
Credit: Elizabeth Paashaus

Comfort

The Catalyst is the workhorse of the ULA line. The recommended max weight is 40 pounds, but we found that to be slightly conservative. We tested this pack with over 45 pounds, and it performed admirably. Whether you are loading this pack with heavy climbing gear or crammed full with a fresh resupply out of a trail town, this pack can take the weight.

The suspension consists of a frame sheet and two (malleable) aluminum stays that transfer load weight to the comfortably padded hip belt. While this style of frame is dated, it still does a great job of redistributing weight off your shoulders and onto your hips. The shoulder straps are padded well and come in the standard J-Straps and S-Straps to fit different body types. The mesh-style foam back panel doesn't breathe as well as a more modern trampoline-style harness, but it is comfortable on your back and dries quickly after a sweaty hike.

ultralight adventure equipment catalyst - the roll-top takes some getting used to if you are accustomed to a... — The roll-top takes some getting used to if you are accustomed to a cinch top with a lid, but getting a good closure is a piece of cake.
Credit: Elizabeth Paashaus

Ease of Use

The Catalyst is loaded with incredibly functional features. It's no wonder ULA rarely changes things up with its line of backpacks. Some of our favorite features include huge side pockets, an excellent front mesh stuff pocket, dual-zippered hip belt pockets, and a front shock cord lashing strap. These features are not revolutionary, but they are undeniably user-friendly.

The large side pockets can hold two tall Smartwater bottles each for those long desert crossings with limited water, but they are useful for much more than just bottles. We found that we could fit rain gear or a pack cover in addition to a single tall bottle. An adjustable shock cord helps keep everything in the pockets contained and secure. The pockets also angle forward, so it is easy to reach back with one hand to remove and reinstall the bottles on the go without taking off the pack.

ultralight adventure equipment catalyst - with huge side pockets, this pack can easily carry up to six liters... — With huge side pockets, this pack can easily carry up to six liters of water (with the use of the internal water bladder sleeve). No desert trail is too long or dry for this pack.
Credit: Elizabeth Paashaus

The Catalyst is advertised as a 75-liter pack. However, it is worth noting that the main compartment is only listed as 43 liters. To account for the remaining capacity, ULA includes the side pockets, the exterior collar, the hip belt pockets, and the stretchy mesh pocket. From our experience, this pack doesn't feel as large as most other 75-liter packs.

The front mesh pocket is another perfectly executed feature. This pocket is huge, encompassing most of the front of the pack, and is an ideal place to stuff light layers, a pack cover, fuel bottles or canisters, and just about anything stuffable that will fit in this large 10-liter capacity pocket. Any bulky layers that won't fit in the stuff pocket can easily be strapped to the front of the pack using the shock cord lashing. This is also an ideal place for a closed-cell foam pad or drying wet socks, bandanas, or underwear.

ultralight adventure equipment catalyst - the shock cord on the front of the mesh pocket can accommodate a... — The shock cord on the front of the mesh pocket can accommodate a huge variety of gear.
Credit: Elizabeth Paashaus

Having exceptionally large and accessible hip belt pockets, they are useful and versatile. We found them perfect for our phones, snacks, map & compass, water treatment, chapstick, and any wrappers or trash found on the trail. The roll-top takes a little getting used to since it has to be buckled on each side, but the simplicity of not having the top lid makes up for the minor inconvenience. However, closing the pack when loaded all the way to the top feels slightly less secure until the top compression strap is fastened and tightened.

ultralight adventure equipment catalyst - large hip belt pockets hold all the small on-the-go items like... — Large hip belt pockets hold all the small on-the-go items like snacks, phone, or a map and compass.
Credit: Elizabeth Paashaus

Weight-to-Volume Ratio

We were blown away by how light this felt when empty. Weighing just under 3 pounds, the Catalyst is an incredibly lightweight pack that performs extremely well, even when loaded with over 40 pounds of gear. Though some other packs we tested weigh about the same, the Catalyst's higher volume gives it a very impressive weight-to-volume ratio that more than makes up for a few extra ounces.

The true minimalist will also love that this pack has multiple removable features (hydration sleeve, hand straps, shoulder strap water bottle keepers, and small internal storage sac). Depending on what configuration you decide, the total weight can be reduced by up to four ounces. The 400 Robic fabric used on this pack is durable and tear-resistant, yet lightweight. The Catalyst also saves weight by keeping the suspension and construction simple.

Adjustability

With four harness sizes available, regardless of your torso size, it's almost guaranteed that there's a Catalyst that will fit. They range in torso length accommodation from 15 to 24 inches. They also offer six separate hip belt sizes to fit a wide range of waist measurements, from 26 to 47 inches.

Finally, they offer two types of shoulder strap shapes: the J-Curve and the S-Curve. J-Curve is their original and works best for most men, but men with certain body types (athletic build) will benefit from the S-Curve. While each pack only has a small amount of adjustment, each size accommodates about four inches of torso lengths, and with some up-front planning, a great fit is easy to get.

ultralight adventure equipment catalyst - compare the s-curve shoulder strap (left) to the j-curve (right). — Compare the S-curve shoulder strap (left) to the J-curve (right).
Credit: Adam Paashaus

Should You Buy the Ultralight Adventure Equipment Catalyst?

If you want a comfortable pack that carries heavy loads well, is impressively lightweight for its volume, and has a great set of features, then the ULA Catalyst is a solid choice. This pack is super light for the amount of weight it can carry comfortably and has useful features for long-distance hiking. If you're on a tight budget, this backpack may seem expensive, considering how simple it is. But for those who want a large carrying capacity, and value-saving weight without sacrificing pocket options, we think this pack is worth the cost.

What Other Backpacking Backpacks Should You Consider?

The time-tested ULA Catalyst is an ideal pack for long-distance hiking — it's lightweight, comfortable, and scales up and down depending on how much food and gear you're carrying. If you're looking for a pack with a few more features, like a top lid and front-panel accessibility, check out the Granite Gear Blaze 60. Check out the Deuter Aircontact Core 65+10 for the most organization and accessibility of any pack we tested. If you're looking for a backpack with a more supportive, breathable, and comfortable back panel, consider the Osprey Atmos 65 AG or Osprey Exos 58.