Ultimate Direction Fastpack 20
“Fastpacking” – a hybrid of trail running and ultralight backpacking – is an exciting way to explore the trails. While this concept has been around several years now and is growing in popularity the industry hasn’t quite caught up yet with the trend yet.
The market is basically segmented between packs tailored specifically for trail running, and packs tailored specifically for backpacking. The backpacking packs are getting lighter but just don’t fit right when you transition from hiking to running. Meanwhile, the trail running packs while very comfortable and lightweight don’t have the capacity to carry overnight gear unless your idea of overnight gear is say, sleeping against a rock. Also, if you’re in bear country you’d be hard pressed to find a running vest capable of holding a bear vault!
Queue the Ultimate Direction Fastpack 20 (Summer ’14, $149). This is this first pack I’ve see that really targets this market and does it very well, containing features that cater to both running and backpacking. In addition I could see how this pack could be used for other activities such as mountaineering or climbing.
Main Features:
- Holds 15 to 20 liters of capacity
- Lightweight – The model I tested was a pre production model but weighed less than 1.5 pounds
- Myriad storage options. Pockets for everything!
- Fits like a running vest
- Adjustment straps, cords, and loops galore to help keep your gear tight and secure when on the move.
- Large, wide mesh shoulder straps to improve comfort.
Fit

The FastPack20 fits like a race vest eliminating the hip belts you normally see in traditional backpacks and relying instead on two adjustable sternum straps. Both straps are on sliders and can be adjusted up or down across the chest and then cinched tight – a good design for both genders. Additionally there are adjustable straps on the sides to ensure a good snug fit to eliminate bounce while running. I found these adjustment options very effective in testing and didn’t feel much bounce at all when running.
Also I should note there are two sizing options available – a Small/Medium pack and a Medium/Large pack. The pack I tested was that latter and fit great. I’m about 5’9”, medium frame, 160lbs.
Storage
When you are trying to cover as many miles in a day as you want to be able to access your essential items quickly and efficiently and not waste time taking your pack off and on to dig for things. So the design of storage is extremely important. I owned the UD Scott Jurek vest and one of my pet peeves was how hard it was to reach the hip pockets. I generally had to take the vest half off to get at them.
What I like about the new FastPack 20 is how UD maximized storage on the front straps. There are a total of 5 accessible compartments on the front:
- 2 water bottle sized pockets. Each one uses a different mechanism to secure the water bottle or whatever items you choose to store in these pockets. The right pocket is zippered while the left pocket can be cinched with a cord. It should be noted the zippered pocket does not hold a hard water bottle very well. But the cord cinched pocket held a 20oz UD bottle perfectly.
- In addition the zippered water bottle compartment has a side pocket. However, there is no lid or cinching mechanisms to secure the items in this pocket you just have to rely on the stretchy meshy material to keep items snug. Good for quick access to a few gels but I wouldn’t store a phone or GPS device in the side pocket for fear of it slipping out.
- 2 pockets beneath the water bottles. One pocket is zippered while the other uses Velcro. Both look to be about the same size.
In addition there are other external storage compartments:
- Large mesh pocket on the back
- Side zippered pocket
- Dual large mesh side pockets. These side pockets are large and can hold anything from a nalgene bottle to tent poles/trekking poles. Tall items can be secured secured via a cord that can cinched and secured to loops along the back of the pack.
Finally, there is a large voluminous internal compartment. The compartment can be reduced or expanded via a roll top cover (common for traditional backpacking packs). Also there is a pocket to accommodate a hydration bladder.
I was pleased that this compartment was just big enough to fit a standard size bear canister.
Hydration
This pack gives you a number of hydration options. It accommodates a hydration bladder as

well as front loaded bottles akin to the AK/SJ/PB signature race vest series. In addition the large side mesh pockets are large enough to hold a nalgene bottle for even more capacity. I like the versatility in this respect. If you’re in an area where water is abundant you can get by on bottles or soft flasks. Then when you move to a region void of H20 for awhile you can fill up the hydration bladder or a nalgene.
Suggestions
Overall this is a very thought out and well designed pack. The only feature I would like to see in the future is a method for storing trekking poles from the front of the pack – so that you don’t have to remove the pack when you want store your poles.
Changes
The full production model will have a few changes from this sample, including:
- The zipper on the front strap pocket will be auto-locking
- The front strap pocket will be slightly larger
- There will be a “scuff pad” – a sheet of highly resistant nylon on the very bottom – to improve long-term durability
- Likewise, there will be a reinforcement strip where the upper pack attaches to the upper straps
Conclusion
When I fastpacked the John Muir Trail in 2012 I struggled to find a pack that could hold all of my gear but would be comfortable enough to actually run in. The backpacking packs – even the ultralight ones – were uncomfortable to run in. The pack I eventually went with (the Osprey Hornet 46l) used very thin shoulder straps to cut down weight. Those straps eventually dug into my shoulders over the course of the trip. So I appreciated the wide mesh shoulder straps in the UD Fastpack 20. I also appreciated the myriad storage options! Without taking the pack off I could access a water bottle, water filter, phone/GPS, and food. That’s ideal for fastpacking. The only time I want to remove the pack is to either take a dip in a lake or setup camp.
Overall I thought this pack had a very thoughtful, versatile design and I’m excited to use this in the future for upcoming fastpacking adventures!
“Buzz asked me to test out the pack over our weekend in an effort to get any/all last-minute feedback before they go into production. I paid extra attention to the pack throughout our adventure. Not surprisingly, I had very little feedback because the UD team had already perfected the design. If you like the fit of the race vests, but simply want more volume, this is the pack for you”
-Jared Campbell (Barkley Marathons 2014 winner)
For more information or purchase, please visit this link.
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This pack was provided to URP as a pre-production sample, and I asked friend Bill Clements to run it through a comprehensive review. Bill loves adventure running and exploring new trails and he’s fast packed the Tahoe Rim Trail, the John Muir Trail, and has run Grand Canyon Rim2Rim2Rim three times. His next big adventure will be running he Ultra Trail Mont Blanc this summer in the Alps. During training he wears a shirt appropriately titled “I eat alps for breakfast”.
All words are Bill’s, and there was no expectation of a positive review.
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