Description
The Purist is part of our Pure Mountain Running line, created for athletes who move through environments where gear is continuously tested by terrain. The primary body of the pack is constructed using challenge cloth, a three-layer composite that pairs high-density polyester with a UHMPE fiber reinforcement layer and a polyurethane film. This creates a fabric that is significantly more abrasion resistant than even military spec fabrics, while remaining exceptionally lightweight and ready to handle sharp rock, brush, and the constant friction of long days in the mountains.
Complementing this is our EnduraMesh XT, a true 4-way stretch mesh that flexes naturally with the body. Unlike typical stretch meshes that degrade under stress, EnduraMesh XT blends Nylon 66 for strength with 30% UHMPE fibers that are rated up to 15 times stronger than steel. The result is a pack that delivers both adaptability and long-term durability, built to move with you while standing up to whatever the mountain throws your way.
Recommended Use:
The Purist is designed for multisport athletes and endurance adventurers who need a versatile, high-capacity pack built to handle everything. Ideal for ultrarunning, adventure racing, mountaineering, and long backcountry adventures where carrying a variety of gear is essential. Perfect for athletes who demand fast access, durable construction, and all-day comfort across unpredictable terrain and changing conditions.
Details:
• 22-liter roll-top design built for multisport and endurance athletes
• Durable construction with premium materials for rugged, all-condition use
• Massive side pockets fit all UltrAspire hydration options and allow fast gear access
• Externally accessible, insulated reservoir sleeve for efficient mid-effort refills
• Large quick-stash outer pocket with compression for secure load management
• Anodized aluminum buckles provide reliable attachment for poles, ice axe, or hose management
• MaxO2 sternum system with adjustable toggle buckle for custom fit and breathability
• Front harness includes a zippered bottle pocket with weather protection
• Layered zippered pocket at the fingertips for quick-access items
• Sweat-proof lined phone pocket keeps electronics protected
• Dual zippered top shoulder pockets for additional organization
Fit:Â Universal
Size(s): 26″-48″
Color:
Hydration (included): Â Not Included
Bottle Compatible (not included): UltraFlask 550 Hybrid Bottle, Softflask 300, 500, 800, Human 20 Bottle, Reservoir
Capacity: 1343 c.i. (22L)
Michael McKnight –
This is hands down my new favorite pack. I had the chance to use a prototype during the 2025 Cocodona 250. The first 35 miles of this course is long and hit with limited access to aid. My plan was to use the Purist for this section only, then switch to the Zygos. I ended up keeping the Purist on for the entire race because I loved it so much. It can store A TON of gear/food/water in it. But, if you don’t need space for a lot of stuff, you can strap it down to be fairly minimal. Seriously, I’m going to be using the Purist for essentially all my future races and adventures.
Jeff Fullmer –
Incredible fit, function, and materials.
I have never worn a pack that is fully loaded and been able to unbuckle the chest straps and have it not pull off my shoulders. The weight distribution and way it hugs you is incredible.
I have used 800 ml soft bottles with the Ultraspire blottle configuration in the outer pouches on the back and without taking it off, can swap hoses from one bottle to the next. 2L bladder works great as well and my quick access items fit great in those two back pouches. Jacket, toiletries, etc.
The front pockets can hold two 800 ml soft bottles as well. You could load up four 800 ml bottles in this and a 2L bladder, without sacrificing very much of your roll top storage and still have stash pockets on the front. That means you could haul almost 1. 5 gallons (5.2 L or 175 oz) of water and not have to stash bottles in the roll top.
Swept a 50k race for 10+ hours and have used it for multiple runs and hikes. It’s as comfortable as any other regular running pack, but with double or triple the capacity and 10 times the durability. Excited to use this for climbing the Grand Teton and snowshoe trips.
Knowing I can use this on a hikes or anything from a 5k to 300-miler makes this my everything pack. It also justifies the price, especially knowing it’s almost bulletproof. Instead of rotating through 3 or 4 packs for different scenerios, I found THE ONE.
Excited for this knew line of products and what else will be coming!
Dandelion Dilluvio-Scott –
As a multi-sport adventure athlete my favorite thing in the world is combining running ultra distances with alpine climbing. Finding the right pack for this combination of sports was tricky though. Unfortunately, traditional climbing packs that have the durability and capacity for light and fast alpine missions are not engineered to be comfortable while running. I was really excited when I learned about the Purist and had the opportunity to test three versions. It’s made for exactly what I love to do most: run and climb!
I spent this past summer playing in the rugged Wyoming Rockies and Purist accompanied me on many advetnures. I can fit everything I need to feel safe on a remote alpine wilderness: bivy, puffy, pants, helmet, small alpine trad rack, 30m rope, traction, hardshell, harness, rock shoes, nutrition, hydration,etc. Even loaded down will all this gear the vest balances perfectly on my body while climbing and sits comfortably on back running without bounce or jostling. The exotic fabrics have outstanding durability and the vest looks like new even after being thrown down haphazardly on talus, dragged through snow on glissades and brushed against granite faces.
Knowing I can comfortably carry everything I need in a reliable vest that can withstand the harshest alpine conditions allows me to fully focus on the adventure! The Purist is the perfect hybrid between a running vest and alpine climbing pack!
Erik Hamilton –
The Purist offers 22-liters of carrying capacity while fitting and riding like a sleek running vest. This pack has been my 2025 go-to for trail runs in the mountains, packing coffee and breakfast for sunrise l-on-the-summit hikes, and a great companion at my first 100-mile trail race.
While I intended to switch out to a different vest if need be, the comfort, packability and intuitive placement of all pockets kept the Purist on my back for the entire race – even discovering the side pockets stash burritos (as well as 800ml soft flasks) beautifully!
This pack has also been my partner in several forested and rugged bushwhack (trailless) adventures and the fabric has yet to show virtually any signs of wear.
Very very pleased with all UltrAspire has put into this running pack. Enjoy!