Red Paw Packs Flatiron 28L Review

An in-depth review of the Red Paw Packs Flatiron 28L fastpack.

By and on May 31, 2022 | Leave a reply

The Red Paw Packs Flatiron 28L ($275) roughly marks the midpoint between small, one-night running fastpacks and larger multi-day fastpacks. It’s capable of carrying enough food for weeklong adventures through high alpine wildernesses, and it also runs well once all that food is gone and you’re headed back to the trailhead.

The Flatiron is a custom-made, medium-high volume, ultralight fastpack made by a cottage manufacturer in Boulder, Colorado. Every pack is made to order, with average lead times of around four months. The Flatiron weighs between 13 and 19 ounces depending on materials and customization. Our pack came in at 19.47 ounces after adding several custom features.

We were impressed by this pack’s volume-to-weight ratio. One of our testers took it on an eight-day on- and off-trail fastpacking trip through the San Juan Mountains of Colorado. That’s a lot of food-carrying capacity for what’s marketed as a 28-liter pack. We also found it to be very versatile, carrying loads of 25 pounds comfortably and running decently well at weights under 12 pounds. For those of you planning longer fastpacking adventures, add the Flatiron to your list of contenders.

We named the Red Paw Packs Flatiron 28L one of the best overall fastpacks in our best fastpacks guide.

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The Red Paw Packs Flatiron 28L - Moab Fastpacking

Testing the Red Paw Packs Flatiron 28L in Utah. All photos: iRunFar/Eszter Horanyi

Red Paw Packs Flatiron 28L Harness and Runnability

The Red Paw Packs Flatiron 28L utilizes a harness unofficially referred to by many as a hybrid fastpacking harness. It is nearly running vest-shaped to contour to the body, but it is also slightly narrower and has more padding than a running vest. We’re not sure who did it first, but this style is becoming more popular, with other brands such as Dandee Packs and Yar.gear also making packs with hybrid fastpacking harnesses.

The Flatiron’s hybrid fastpacking harness is highly padded, making it very comfortable all-day movement through the mountains with over 20 pounds inside. It’s a little overpadded for a fastpack, however, and felt like overkill at lower weights.

Many iRunFar testers prefer harnesses to be less padded for breathability and body contouring. That said, the three-dimensional mesh on the back of the straps did effectively keep sweat away from the body.

With lower weights, we found the Flatiron to run comfortably. The harness effectively snugs the pack to the body, so the removable webbing waistbelt was unnecessary for supporting weight or stabilizing the load. Carrying over 15 pounds was a different story. The load wanted to shift side to side when scrambling and jogging, so the waistbelt became helpful for keeping the pack stable against the back.

Red Paw Packs Flatiron 28L - fastpacking scrambling

Using the Red Paw Packs Flatiron 28L to scramble in Colorado.

Red Paw Packs Flatiron 28L Materials

When we ordered our Red Paw Packs Flatiron 28L in 2021, we had it made from a Dyneema Composite Fabric (DCF) hybrid. We have appreciated the water resistance of this fabric but have been a little annoyed by the initial stiffness, although it has softened up over time, making it ride more comfortably.

Red Paw Packs no longer offers DCF hybrids but does offer the Flatiron in a variety of other materials. They, like many other cottage companies, have started making packs out of EPL200 Ultra, a new extremely durable material from Challenge Sailcloth. We would probably consider ordering this pack in EPL200 Ultra, as it would make the pack even lighter and more durable and give it a more malleable feel. Classic X-Pac VX21 is also available as a tried-and-true option, with medium durability, medium weight, and low cost.

Red Paw Packs Flatiron 28L - front view

A front view of the Red Paw Packs Flatiron 28L.

Red Paw Packs Flatiron 28L Storage Options

The main body of the Red Paw Packs Flatiron 28L is a large tube-shaped rucksack four inches deep, 12 inches wide, and 28.5 inches fully unrolled. In our opinion, this pack is quite a bit larger than most packs claiming to be around 30 liters in volume.

We were able to pack a small, ultralight sleeping bag horizontally with a sleeping pad, cook kit, tarp, and food on top of that. A three-season kit fills up only about half of the pack, leaving the rest of the volume for food. One of our testers fit eight days of food plus a three-season kit in the Flatiron.

The Flatiron comes with two big wrap-around Spandura pockets on the body of the pack that are essentially both side pockets and rear pockets simultaneously. They are quite large, accommodating snacks, layers, water bottles, trekking poles, and other accessories. They’re so large, however, that they can start to function as junk drawers if you aren’t careful, accumulating bar wrappers, sunscreen, and unworn clothing in an unorganized tangle.

The Flatiron’s unique underneath pocket is higher in volume than most underneath pockets we’ve come across. Our testers kept gloves, gels, and rain gear in it. We found it to be exceptionally secure when wearing the pack, but sometimes when we took the pack off and set it on the ground, items were at risk of falling out.

The hybrid fastpacking harness on the Flatiron provides a wide template for shoulder strap pockets. The two Spandura water bottle pockets fit 500-milliliter soft flasks and water bottles but do not have shock cord closures to keep them from bouncing out.

It’s fortunate that Red Paw Packs offers customization because we were able to add closures to these pockets, but we believe this pack should come stock with these drawstring closures. Above these bottle pockets are small pockets for gels, bars, and other snacks.

Red Paw Packs Flatiron 28L - back view

A back view of the Red Paw Packs Flatiron 28L.

Red Paw Packs Flatiron 28L Customization

Our testers loved the fact that we were able to add a zipper to one of the smaller shoulder strap pockets, shock cord drawstrings to both the larger shoulder strap pockets, and shock cord to the back of the Red Paw Packs Flatiron 28L.

But customization is a double-edged sword because when every pack is made to order, the lead times get very long. This sort of custom pack will best suit someone who knows exactly what they want and who refuses to settle for stock packs made by major manufacturers. Naturally, custom items are non-refundable and non-returnable which could be a pain if your hoped-for pack doesn’t work perfectly when you receive it four months later.

Red Paw Packs Flatiron 28L - side view

A side view of the Red Paw Packs Flatiron 28L.

Red Paw Packs Flatiron 28L Overall Impressions

Overall, we loved the Red Paw Packs Flatiron 28L but would like to see a few improvements. We would like the shoulder strap pockets to come stock with shock cord closures for securing water bottles. Secondly, the Flatiron is light but not as light as some other packs in the fastpacking category, especially if you start adding custom features.

We also found ourselves occasionally grimacing at the aesthetic of the fully loaded Flatiron, as it looked a bit tall and dorky at times. Once it got down to about 20 liters, however, it looked quite nice. Other packs such as the Pa’lante Packs Joey — check our Pa’lante Packs Joey review — or the Mountain Laurel Designs Burn 38L just look more sleek and polished. But Red Paw Packs hasn’t been in existence for very long, so we assume that the Flatiron will get more polished over time.

Those are minor complaints, though. We loved being able to customize our pack. The Flatiron also has an impressive volume-to-weight ratio for being only about 19 ounces and clearly much larger than 28 liters. It is also highly versatile, working well for both weeklong powerhiking trips and overnight running adventures.

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Call for Comments

  • Are you using the Red Paw Packs Flatiron 28L? If so, for what kinds of outings do you use it?
  • What other fully custom fastpacks should we have on our radar?
  • Is customization worth the long lead time?

[Editor’s Note: If you’re affiliated (i.e., an employee, ambassador, etc.) with a brand, please share your relation in each of your comments on this article. Thanks!]

Red Paw Packs Flatiron 28L - fastpacking - Colorado - Meghan Hicks

iRunFar’s Meghan Hicks uses the Red Paw Packs Flatiron 28L on an eight-day fastpacking trip in Colorado.

Ben Kilbourne

Ben Kilbourne is a Gear Tester, Writer, and Editor at iRunFar. He’s been writing about ultralight backpacking and fastpacking, as well as the intersection of these types of recreation with environmental issues for four years. Aside from iRunFar, he has written for publications including Backpacker Magazine, Backpacking Light, Dark Mountain, and Section Hiker. Based in Salt Lake City, Utah, Ben explores all over the west, but especially the canyon country of the Colorado Plateau. His experiences on the land, whether triumphant or thwarted by events either in or out of his control, have provided the foundation for his essays, paintings, articles, and songs.


Ben Kilbourne
Meghan Hicks is the Managing Editor of iRunFar and the author of 'Where the Road Ends: A Guide to Trail Running.' The converted road runner finished her first trail ultramarathon in 2006 and loves using running to visit the world's wildest places.