ULA Catalyst Backpack: In-Depth Review

The Catalyst was my go-to pack for three years. Lightweight, durable, and able to carry surprisingly heavy loads comfortably, it is a trusty ultralight pack.

The ranger walked with the easy lope of someone who spends most of the summer hiking, and her backpack immediately caught my eye. It was distinctive; yellow bungee cords, a green fabric with a white grid, and a large side pocket filled with a handsaw and water bottle. She was in the middle of a six day backcountry monitoring trip, and I briefly talked with her. Somehow the topic of her pack came up, and she raved about how comfortable and durable it was. This was six years ago, and when I was ready to switch to a lighter backpack, I remembered the ranger, and that distinctive green pack.

It was the ULA Equipment Catalyst.

I got my own Catalyst backpack in 2021, and it became my go-to pack immediately. Lightweight, durable, and able to carry surprisingly heavy loads comfortably, it is my trusty adventure companion with many trips under our belt.

The Short Version

• The things I love the most: This pack has an exceptionally balanced fit that hugs my back and is stable. It can also carry loads over 40 lbs, is really durable, and easily fits all the gear I throw at it (including a bear cannister placed horizontally!). The pockets are all great sizes, especially the hip belt pockets that fit a lot of stuff.

• With loads pushing 40+ lbs (heaviest I’ve done is 48), the shoulder straps do become uncomfortable and I have to adjust them often.

• Small nitpicks: I wish the sternum strap could move up a wee bit higher, and the shoulder straps can get smelly if I wear a synthetic shirt for days

• Recommended addition: The shoulder strap pocket from ULA. I love this thing. It carries my phone, inReach mini, sunscreen, and a snack. I love it so much.

  
  

I bought this pack full-price, and talk more about the value for the weight savings below.

The Long Version

Prior to the Catalyst my pack was the Gregory Deva, which I used for over a decade. My Dad got it for me and I took it on trips all over Washington and to the summit of two volcanoes. It was my workhorse and allowed me to carry a heavy pack with ease, but it was also astoundingly heavy when I finally weighed it – almost six pounds. With the onset of the pandemic, I found myself carrying all my own equipment (no more sharing of tents or cooking supplies) on trips with friends and scientists, and I began looking for ways to reduce my pack weight.

I looked at everything I carried, and quickly realized that I was not going to be a full-on ultralight hiker. I have to carry every essential for myself, along with a pound of painting equipment and two pounds of camera gear to film my Adventure Art Academy classes. And I like to be warm so I have one too many puffy jackets with me at all times. Lightening these items was prohibitively expensive or simply not an option, so the pack became my target.

I spent a long time looking, and tried on a lot of packs at REI (or ordered and wore them around the house). The Hyperlite packs didn’t carry heavy loads well and had too narrow of a yoke around my neck. A lightweight Gregory didn’t distribute weight to my hips, and the materials were fragile. The Osprey Exos also didn’t carry more than 25 lbs well.

I was running out of options, and then I remembered the fortuitous conversation with the ranger, and immediately emailed ULA to ask for their advice on which pack they recommended. I talked with both Chris and Pete at various times over a phone call and multiple emails. They recommended the Catalyst as the best fit for my intended weight range of 25-40 lbs. I was also really impressed that they also helped me figure out the best sizing for the pack, especially the J vs the S straps.

After two years of using the pack, I am really happy with it, and wholeheartedly recommend it. The rest of my review dives deeper into the pack’s features and what I thought of them.

The Specs

• The Catalyst weights 44.4 oz (2.78 lbs) and is rated to carry up to 40 lbs.

• Capacity- 75 liters. This high number includes the extra space in all the pockets and extending the collar of the pack. The main compartment is 42.6 liters. The overall volume, with the pockets, feels comparable to my old Gregory Deva’s 65 liters (70 ish with the collar up). More than enough capacity for me, even on a nine-day trip with a bear cannister.

• My full-size bearvault fits horizontally in the pack!!

• Pockets: two large side pockets (5.7 liters each), two hip belt pockets, and one big front pocket (9.8 liters)

• Material that I got- Royal blue robic. Peter said that the robic is still his favorite pack material because of its outstanding durability (and the x-pac fabrics were simply too expensive for me!)

• Size: medium torso (18-21 inches according to their site. For reference, my torso is 20 inches, on the longer side for women). There is some adjustability in this - you can move the hip belt up and down a few inches.

• Medium hip belt, J shoulder straps.

Load Carrying Ability

The Catalyst has a stated max recommended load of 40 lbs. For me, the pack is the most comfortable in the sub-38 lb range, which makes complete sense given the recommended max. But, I have carried over 40 regularly and even up to 48 lbs a few times and it did serviceably well, with some shoulder pain and relatively frequent adjustments of the straps to shift the pressure. For my body shape, so far no pack is super comfortable at those higher loads because it is nearly 40% of my total bodyweight, and my shoulders eventually get sore. At this higher end I am pushing the Catalyst beyond its intended range, so it is impressive that it does so well.

August 2024 update: I’ve now taken this pack on two nine-day backpacking trips in the Olympic mountains where my starting pack weight is pushing 47-48 lbs due to carrying 9 days of food, bear can, and all of my own equipment (no shared supplies) plus watercolor paper and my painting kit. The first few days were definitely not the most comfortable on my shoulders, and I am now on the hunt for a pack with a similar light weight but a higher weight capacity for trips like this.

The Catalyst has the most robust frame of the ULA pack range with two aluminum stays that support the internal frame sheet. These stays can be bent to match your spine’s shape – more on that below.

It is also worth noting that the Catalyst compresses down wonderfully for excursions from camp. Unlike my old Gregory that always seemed to flop around or sag way down, the Catalyst is easy to cinch in with the side compression straps, and the lack of a brain at the top of the pack means the upper strap can pull the whole together tightly.

Lastly, I often fill my packs with pillows and hand weights for training walks. I found that the pack carries the best on an actual trip when the main body of the pack is efficiently full of my things, because this is a more even distribution of weight than what I get with weights. Don’t judge the fit/ comfort until you’ve actually put all your gear in there!

Back Panel and Frame Stays

I got the pack with a medium hip belt and medium torso length. With a 20-inch torso I am right in the medium range, but Peter recommended that I not size up (to avoid having the loaded pack be too high right behind my head, especially if I ever wore a helmet). ULA’s website is much better than it used to be with easy to find and helpful sizing guides.

Two of my favorite things about this pack are that I could contour the two aluminum stays to match my back, and that it does not have the anti-sweaty-back trampoline / separated back panel nonsense. The pack contours to my back nearly perfectly, and yes, my shirt does get sweaty, but I’m working hard hiking so that is to be expected. I have never found the pack to be too hot, even in 97 degree weather.  The material of the back panel does get damp if I’m working hard, but it is a dense mesh and dries quickly.

And I will happily trade a sweaty back for how insanely stable this pack feels.

Bending the stays to match my back made a pretty big difference in the comfort- it took it from average to really good. Bending them is easy, but be sure to trace the original shape on some cardboard or paper so you can get them back to that starting state as needed. I simply pulled them from the little sleeves and INCREMENTALLY adjusted the curvatures until it matched me well.

Tips for bending the stays:

• Take it slow. It is much harder to unbend than it is to bend

• Stuff the pack with pillows for each fitting after adjusting the stays, because the pack sits differently full vs empty.

• Work incrementally. It took about 40 minutes of fussing, but I eventually got it really close, and then made a final adjustment after my first few hikes.

• When you first pull out the stays, use a sharpie to mark left, right, front, and up before they are fully out of the pack. This helps make sure you can get them back in properly.

• I used the shape of my day pack from Arc’teryx to help as well, because the frame of that pack bent to match my body after three years of use, so it was a helpful starting point.

  
  

Now that the frame matches my back, the pack is amazingly stable. Compared to my old pack, the Catalyst feels like it is right there with me when I move, and this is huge deal when I’m on steep and off trail terrain. I really noticed this when I was navigating a bushwhack on a 35+ degree slope- I did not feel pulled backward, and when I leaned into odd positions around trees the pack did not swing around.

The longest trip I did with the pack so far was 9 days in the Olympics. My pack was the heaviest ever - 47 lbs on day one, oof - and the Catalyst did great considering how far I was pushing it above the recommended max. The bear cannister fitting sideways meant I still had plenty of space for my other gear, and I adored the hip pockets more than ever to store my snacks in so I could eat on the move.

Shoulder straps

I elected for the J shaped strap because my shoulders are flatter on top, and because I have a very small chest and don’t need the boob/ chest space of the S-shaped straps (the ULA website says the S straps are best for most women, or folks with broader chests and sloping shoulders). The straps contour to my body well, and seem to avoid any big pressure points. The straps also have a wider yoke than some other ultralight packs, so I never have problems with the straps irritating my neck.

In the Catalyst my shoulders will get a bit sore if my load is pushing 40 lbs, but this happens in every pack I use. But, I have no chaffing or rubbing. I find that fine-tuning the fit with the load lifters also makes a big difference. Too loose, and the pack can put too much weight onto the tops of my shoulders instead of the front of my chest where I prefer. I love the load lifters, and would likely never buy an overnight pack without them.

Something special on this pack is that you can also adjust where the load lifter links with the shoulder strap thanks to a sliding attachment. This is an awesome feature that I usually see on more expensive expedition packs.

As with any pack, tightening the hip belt, then shoulder straps, then load lifters, will help make sure the pack is sitting properly on your body. I find that I fiddle with the load lifters a lot if I’m in the 40+ range, and sub 35 I barely touch them.

The shoulder straps do, however, have the only area of complaint for this pack- they can get sinky! The last few inches of the straps wrap under my arms, and on a longer trip any smell from a synthetic shirt transfers to the fabric of the strap and refuses to leave until washed. This is just a minor irritant, and I just wash the straps after every few trips which is a little tedious but keeps them nice and clean and prevents the stink from transferring to my raincoats etc.

Lastly, the sternum strap does fall lower than on my other packs. While it works just fine, I do sometimes wish I could slide it higher to shift the load around on longer days.

Hip Belt

The distribution of weight from my shoulders to the hip belt is also quite good. Better than all the other light packs I tried. With the heaviest loads I do still feel like the pack isn’t dumping as much weight on my hips as I would like, but this is likely not a flaw in the pack, and more me pushing it to carry more than designed.

The hip belt fit is really nice- it is thick and comfortable, and I think the best of any of the ultralight class packs that I tried on. I think it would likely work for quite a few body shapes because of the two adjustment buckles on each strap. These buckles allow you to tighten or loosen the top and bottom of the belt independently (so, for example, you could have the belt flare out more on the bottom edge). Sometimes I do miss the ultra-plush hip belt of my old Deva, but the Catalyst’s belt does it’s job well, and it also causes far less bruising on my hip bones than my other packs which makes a big difference for me.

The dual-adjustment buckles also allow me to really dial in the tightness of the top vs the bottom of the belt to prevent it from digging into my stomach like the Gregory pack did.

The hip belt also has an extra strap on the back of each hip that connects the belt to the pack body. These straps make the pack even more stable because they connect the weight to my hips and reduce lateral sway. Again, on steeper or more uneven terrain this helps me feel more balanced in the pack.

Lastly, the hip belt also attaches to the inside of the pack with Velcro, allowing us to move it up and down a little to dial in a good torso fit. It worked well for me.

(side note- if your hip bones are prone to bruising like mine, I highly recommend taking your pack for regular walks around the neighborhood with progressively heavier weight, as I have found that this gets the skin a little toughened up, and I get the bruises out of the way. After a few weeks of walks, I never have problems on my trips anymore).

Layout & Organizing gear

With no pack brain, adjusting to the layout of this pack took a little bit of fun experimenting before and during my first few trips. My previous pack had a GIANT top brain compartment and two big side pockets above smaller water bottle holders. Without these pockets I had to come up with a new organization system, that I now like better.

Here’s how I organize my gear, shared not because this is best way to do it, but to give you an idea of what the compartments can fit.

• Side pockets – these are HUGE! On one side I have two platypus one-liter bottles plus my little sawyer squeeze tucked in the corner (and clipped to a strap). On the other side I have my first aid/ ten essentials kit and my tent poles with a large piece of watercolor paper wrapped around them.

• Front pocket: raincoat, rain pants, pack cover, sack with TP and toiletries, and sack with other extra items like gloves, hat, and flashlight. I needed this extra stuff sack to corral the items that were previously thrown in the brain of the old pack.

• Hip Pockets- sony rx 100 camera and case in one, other is full of snacks and bug net

• Main compartment: sleeping bag, down jacket, synthetic jacket, baselayers in a sack, tent body (Hilleberg Akto), MSR windburner stove, camp shoes, food bag, mini painting and filming kits in Ultralite Sacks zippered bags.

• In the main compartment, because the pack is so wide, I can fit a bear cannister sideways which is awesome. I find that I can pack this space efficiently, even when I keep things in stuff sacks (I am not a free-for-all stuff everything in person- I like to have it all organized and layered well with any empty space filled with a smaller item)

• Front Shock Cord- sit pad and watercolor paper bundle in a Tyvek sleeve

  
  

The side compression straps and top strap lock everything down very effectively. The top strap is also very convenient for holding on “Mr. Stinky” aka the jar that I use to carry out my human waste bags and that you’ll see in a lot of photos. (Note- I added a little seatbelt to Mr. Stinky that the strap threads through after he tried to escape down a snowfield).

I added the ULA shoulder strap pocket as well, which perfectly holds my Iphone 11, small sunscreen, and inreach mini.

Durability

My very first trip with this pack involved a rather heinous bushwhack. Steep slopes and mountain hemlock just over head height that made a jumbled mess of trunks and branches that I scraped through frequently. When I got to camp, I was shocked to see that the Catalyst’s robic fabric looked brand new. My rolled watercolor paper, on the other hand, was absolutely covered in scratches and dents.

After two summers of use, including a few trips over a week each, the fabric still looks perfect. Now, I will note am somewhat careful with all my gear – I never throw the pack down on the ground, and I sit on a sit pad most of the time instead of my pack. For me, this is just best practice if I want to prolong the life of any ultralight equipment.  

So far, the only damage the pack sustained were a few tiny chewed strap edges from a snowshoe hare in the Olympic mountains. When I noticed the frayed edges, I used a lighter to carefully melt the fibers toe the rest of the healthy strap, and was good to go. I also got a bunch of pitch on it at one point, and hand sanitizer took care of that.

Cost and Value

All in, my pack cost just over $300. While this is expensive, it reduced my overall pack weight by 3 pounds, so I effectively paid $100 per pound of shed weight. If I were to try to shed this weight elsewhere – from a tent, or sleeping gear, for example – it would cost me a LOT more for that equivalent pound, or would also come at the cost of a less warm bag.

External Compression / Attachment Straps

I love the simple straps on this pack. The top strap works well to close the roll-top and stabilize the top of the load. It also excels at making the pack smaller for day trips.

On the sides, the pack has one compression strap above each pocket. These help pull the load in toward my core, and also work very well for holding in taller items that are stuck in the pockets, such as my tent poles (note: I always tie a backup knot on the tent pole bag to the strap to make 100% sure I can’t lose them, especially if I’m bushwhacking). These side straps are also plenty long enough to wrap around a pair of shoes.

Coming from a pack that had an over abundance of straps, I have come to love the simplicity of the Catalyst and how easy it is to load once I got my new system down.

Lastly, I also like how the pack follows a “short and squat” format instead of the usual tall and narrow of most other brands.

If you have any questions, drop them in the comment section below! Thanks for reading this far!