close up on frame

ULA Ultra Circuit Review

The Classic Thru-Hiker Backpack, now in Challenge Ultra Fabric

The ULA Ultra Circuit Backpack (shop now) is an absolutely top tier, cream of the crop, comfortable, indestructible, ultralight-yet-voluminous backpacking pack. Designed for thru-hiking, but perfect for all multi-day excursions, the ULA Ultra Circuit is made with best in class Challenge Ultra fabric, its namesake upgrade to the original Robic Nylon version. We recommend this backpack extremely highly.

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2024 Update: This review was originally published in Summer 2023, and depicts that version of the pack. Since then, ULA has made a few small improvements to the already-excellent design. This includes switching the single line top strap to a Y-strap; use of UltraX fabric to improve laminate durability; and the addition of bottom straps and ice axe/trekking pole straps now come standard.

ULA Ultra Circuit Backpack Stats

  • Weight: 33.8 oz
  • Price: $380
  • Materials: Challenge ULTRA 400/200
  • Frame: Aluminum stay, carbon fiber & plastic U-shaped suspension hoop, dense foam back panel
  • Load Capacity: 35 lbs
  • Internal Volume: 45L
  • External Volume : 23L
  • Pros: Ultralight. Waterproof fabric. Incredibly durable. Voluminous. Comfy. Excellent buckles and straps.
  • Cons: Expensive. Rounded bottom doesn’t sit upright while loading. Not seam taped.

side view of ula ultra circuit backpack

ULA Ultra Circuit Backpack Construction

In summary, the ULA Ultra Circuit is a near-waterproof, roll-top closure pack with large external pockets and a simple-yet-highly-functional frame comprised of one aluminum stay, a suspension hoop, and foam back panel with aerated spacer mesh on the surface. The frame is sufficiently sturdy to host load lifters on the shoulder straps, further increasing the comfort of this pack.

close up on load lifters

Everything about the ULA Ultra Circuit Backpack is simply put, burly. From the buckles to the straps, you can tell that this pack was designed to stand up to the rigors of a complete thru-hike. The foam padding with aerated spacer mesh on the back, hip belt, and shoulder straps is comfortable without being squishy or feeling like it will pack down after the first few trips.

close up on back panel

No ULA Ultra Circuit review is complete without mention of Challenge Ultra Fabric. This relatively new-to-market wonder fabric from sailcloth brand Challenge offers a performance upgrade over previously best-in-class Dyneema.

close up on challenge ultra 400

It is waterproof, ultralight, and incredibly durable. Ounce for ounce, it is 15x stronger than steel, and 20% lighter weight and 4x more abrasion resistant than similar thickness Dyneema. And performance-wise, it simply crushes top tier nylons like Cordura and Robic.

The ULA Ultra Circuit uses a combination of 200 weight and 400 weight UltraWeave. 400 (dark gray) along the bottom, back, and pockets for maximum durability. 200 (light gray) along the sides, front and collar.

ULA Ultra Circuit Backpack Features

For starters, we’re prepared to say this pack has the best set of buckles, straps, and cinches we’ve ever used.

We love how the removable hip belt has dual reverse pull adjusters on each side, dispersing the pressure evenly and ensuring you will enjoy an incredibly comfortable fit. The plastic hardware has extra surface area, forming a lip that is easy to pull back on for intuitive adjustments.

ULA Ultra Circuit Hip Belt

Two full sized hip belt pockets are present. Made of structural stiff Ultra 400, they really hold a nice boxy shape for snack storage. While at first it seems like the YKK waterproof zipper entry to the hip belt pockets are a bit small, this is intended to prevent items from spilling out of a lower opening. What’s more, reducing the length of the zipper track prevents it from sustaining damage when torqued at odd angles.

close up on hip belt pocket

Each of the large-and-in-charge side pockets is wide and deep enough to hold a pair of smart water bottles, or a set of ultralight rain gear. We love that each pocket has a shock cord cinch to close or grip down on your gear or water bottle to prevent it from falling out.

ula ultra circuit side pocket

The extremely deep and voluminous external rear pocket, made with UltraStretch, is both very large, and exceptionally stretchy. It might be the best stretch-mesh rear pocket we’ve ever used. In it there is room to store tons of knickknacks, snacks, and clothing accessories like a fleece, a hat, gloves, rain gear, etc. The rear pocket is crisscrossed with heavy duty shock cord, perfect to attach a few more light items, like a sit pad or storing a fleece externally.  Ice axe/trekking pole loops are present when you need them.

close up on rear stretch mesh pocket

Two nylon webbing volume adjuster side straps near the top of the pack allow you to shrink down the capacity when not maxed out. But these also make for exceptional sock drying racks and are great to lock down the top of a Sawyer filter.

close up on side compression straps

The pack we reviewed had a pair of ULA Flow water bottle shoulder mounts, as you can see in the photos. But these are sold separately. They’re perfect for storing a Smartwater, but the static mesh and narrow opening makes it impossible to put a bottle in one-handed, and sometimes even difficult with two hands.

What could be better?

We absolutely adore hiking with the ULA Ultra Circuit, and have rarely ever had less to nitpick. Sure, at $380 it’s quite expensive. However, that price point is well in line with other top tier made-in-America backpacks constructed with fabrics like Challenge ULTRA or Dyneema. The only thing they don’t give you is taped seams, which means despite the waterproof fabric, you should still use liners or dry bags.

Perhaps our biggest pet peeve on this backpack is its inability to sit upright when placed on the ground when loading. You have to lean it against something or it will fall over. This is due to the fact that the designers have cropped the rear bottom so it rounds and curves upward and outward, rather than forming 90 degree angle between bottom and rear surfaces.

bottom of ula ultra circuit backpack

However, this configuration is beneficial while actually hiking. The more gear you have loaded into the bottom rear of a pack, the more it subtly pulls you backward, changes your center of gravity, and slows you down. So it’s a give and take. That being said, if you are careful to store only lightweight gear in the bottom of a pack, for example a down sleeping bag, the pull-back effect is largely negated and loading/unloading the pack becomes much more user friendly.

ULA Ultra Circuit Review Verdict

Relative to its 33.8 oz weight, the ULA Ultra Circuit is arguably the most durable, comfortable, and functional, backpacking pack available. From perfect nylon strap adjusters, to the best-in-class Challenge Ultra fabrics suite, we give our strongest seal approval to the designer’s choice of features and materials across the board. Simply put this backpack is excellent. We recommend to thru-hikers and weekend warriors alike. You cannot go wrong with the ULA Ultra Circuit.

side view of ULA Ultra circuit backpack

close up detail on ULA logo

Compare this to more great options in our guide to the best ultralight backpacking backpacks of the year.


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